diff --git a/src/netops.c b/src/netops.c
index 2d759fd58..e2fec0b48 100644
--- a/src/netops.c
+++ b/src/netops.c
@@ -46,7 +46,7 @@ static void net_set_error(const char *str)
 }
 #endif
 
-void gitno_buffer_setup(gitno_buffer *buf, char *data, unsigned int len, int fd)
+void gitno_buffer_setup(gitno_buffer *buf, char *data, unsigned int len, GIT_SOCKET fd)
 {
 	memset(buf, 0x0, sizeof(gitno_buffer));
 	memset(data, 0x0, len);
@@ -60,17 +60,13 @@ int gitno_recv(gitno_buffer *buf)
 {
 	int ret;
 
-	ret = recv(buf->fd, buf->data + buf->offset, buf->len - buf->offset, 0);
-	if (ret == 0) /* Orderly shutdown, so exit */
-		return 0;
-
+	ret = p_recv(buf->fd, buf->data + buf->offset, buf->len - buf->offset, 0);
 	if (ret < 0) {
-		net_set_error("Error receiving data");
+		net_set_error("Error receiving socket data");
 		return -1;
 	}
 
 	buf->offset += ret;
-
 	return ret;
 }
 
@@ -97,12 +93,12 @@ void gitno_consume_n(gitno_buffer *buf, size_t cons)
 	buf->offset -= cons;
 }
 
-int gitno_connect(const char *host, const char *port)
+GIT_SOCKET gitno_connect(const char *host, const char *port)
 {
-	struct addrinfo *info, *p;
+	struct addrinfo *info = NULL, *p;
 	struct addrinfo hints;
 	int ret;
-	GIT_SOCKET s;
+	GIT_SOCKET s = INVALID_SOCKET;
 
 	memset(&hints, 0x0, sizeof(struct addrinfo));
 	hints.ai_family = AF_UNSPEC;
@@ -110,36 +106,30 @@ int gitno_connect(const char *host, const char *port)
 
 	if ((ret = getaddrinfo(host, port, &hints, &info)) < 0) {
 		giterr_set(GITERR_NET, "Failed to resolve address for %s: %s", host, gai_strerror(ret));
-		return -1;
+		return INVALID_SOCKET;
 	}
 
 	for (p = info; p != NULL; p = p->ai_next) {
 		s = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
-#ifdef GIT_WIN32
 		if (s == INVALID_SOCKET) {
-#else
-		if (s < 0) {
-#endif
-			net_set_error("Error creating socket");
-			freeaddrinfo(info);
-			return -1;
+			net_set_error("error creating socket");
+			break;
 		}
 
-		ret = connect(s, p->ai_addr, p->ai_addrlen);
+		if (connect(s, p->ai_addr, (socklen_t)p->ai_addrlen) == 0)
+			break;
+
 		/* If we can't connect, try the next one */
-		if (ret < 0) {
-			close(s);
-			continue;
-		}
-
-		/* Return the socket */
-		freeaddrinfo(info);
-		return s;
+		gitno_close(s);
+		s = INVALID_SOCKET;
 	}
 
 	/* Oops, we couldn't connect to any address */
-	giterr_set(GITERR_OS, "Failed to connect to %s", host);
-	return -1;
+	if (s == INVALID_SOCKET && p == NULL)
+		giterr_set(GITERR_OS, "Failed to connect to %s", host);
+
+	freeaddrinfo(info);
+	return s;
 }
 
 int gitno_send(GIT_SOCKET s, const char *msg, size_t len, int flags)
@@ -150,7 +140,7 @@ int gitno_send(GIT_SOCKET s, const char *msg, size_t len, int flags)
 	while (off < len) {
 		errno = 0;
 
-		ret = send(s, msg + off, len - off, flags);
+		ret = p_send(s, msg + off, len - off, flags);
 		if (ret < 0) {
 			net_set_error("Error sending data");
 			return -1;
@@ -159,7 +149,7 @@ int gitno_send(GIT_SOCKET s, const char *msg, size_t len, int flags)
 		off += ret;
 	}
 
-	return off;
+	return (int)off;
 }
 
 
@@ -187,7 +177,7 @@ int gitno_select_in(gitno_buffer *buf, long int sec, long int usec)
 	FD_SET(buf->fd, &fds);
 
 	/* The select(2) interface is silly */
-	return select(buf->fd + 1, &fds, NULL, NULL, &tv);
+	return select((int)buf->fd + 1, &fds, NULL, NULL, &tv);
 }
 
 int gitno_extract_host_and_port(char **host, char **port, const char *url, const char *default_port)
@@ -198,8 +188,8 @@ int gitno_extract_host_and_port(char **host, char **port, const char *url, const
 	slash = strchr(url, '/');
 
 	if (slash == NULL) {
-			giterr_set(GITERR_NET, "Malformed URL: missing /");
-			return -1;
+		giterr_set(GITERR_NET, "Malformed URL: missing /");
+		return -1;
 	}
 
 	if (colon == NULL) {
diff --git a/src/netops.h b/src/netops.h
index 01ad9714f..f370019ff 100644
--- a/src/netops.h
+++ b/src/netops.h
@@ -7,11 +7,7 @@
 #ifndef INCLUDE_netops_h__
 #define INCLUDE_netops_h__
 
-#ifndef GIT_WIN32
-typedef int GIT_SOCKET;
-#else
-typedef SOCKET GIT_SOCKET;
-#endif
+#include "posix.h"
 
 typedef struct gitno_buffer {
 	char *data;
@@ -20,12 +16,12 @@ typedef struct gitno_buffer {
 	GIT_SOCKET fd;
 } gitno_buffer;
 
-void gitno_buffer_setup(gitno_buffer *buf, char *data, unsigned int len, int fd);
+void gitno_buffer_setup(gitno_buffer *buf, char *data, unsigned int len, GIT_SOCKET fd);
 int gitno_recv(gitno_buffer *buf);
 void gitno_consume(gitno_buffer *buf, const char *ptr);
 void gitno_consume_n(gitno_buffer *buf, size_t cons);
 
-int gitno_connect(const char *host, const char *port);
+GIT_SOCKET gitno_connect(const char *host, const char *port);
 int gitno_send(GIT_SOCKET s, const char *msg, size_t len, int flags);
 int gitno_close(GIT_SOCKET s);
 int gitno_send_chunk_size(int s, size_t len);
diff --git a/src/odb_pack.c b/src/odb_pack.c
index 1a1fa55c5..b91e3cadb 100644
--- a/src/odb_pack.c
+++ b/src/odb_pack.c
@@ -212,7 +212,7 @@ static int packfile_load__cb(void *_data, git_buf *path)
 	struct pack_backend *backend = (struct pack_backend *)_data;
 	struct git_pack_file *pack;
 	int error;
-	size_t i;
+	unsigned int i;
 
 	if (git__suffixcmp(path->ptr, ".idx") != 0)
 		return 0; /* not an index */
@@ -266,7 +266,7 @@ static int packfile_refresh_all(struct pack_backend *backend)
 static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backend, const git_oid *oid)
 {
 	int error;
-	size_t i;
+	unsigned int i;
 
 	if ((error = packfile_refresh_all(backend)) < 0)
 		return error;
@@ -298,7 +298,7 @@ static int pack_entry_find_prefix(
 	unsigned int len)
 {
 	int error;
-	size_t i;
+	unsigned int i;
 	unsigned found = 0;
 
 	if ((error = packfile_refresh_all(backend)) < 0)
@@ -423,7 +423,7 @@ static int pack_backend__exists(git_odb_backend *backend, const git_oid *oid)
 static void pack_backend__free(git_odb_backend *_backend)
 {
 	struct pack_backend *backend;
-	size_t i;
+	unsigned int i;
 
 	assert(_backend);
 
diff --git a/src/oid.c b/src/oid.c
index 7f0a520aa..d072f0ff6 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -260,6 +260,8 @@ git_oid_shorten *git_oid_shorten_new(size_t min_length)
 {
 	git_oid_shorten *os;
 
+	assert((size_t)((int)min_length) == min_length);
+
 	os = git__calloc(1, sizeof(git_oid_shorten));
 	if (os == NULL)
 		return NULL;
@@ -270,7 +272,7 @@ git_oid_shorten *git_oid_shorten_new(size_t min_length)
 	}
 
 	os->node_count = 1;
-	os->min_length = min_length;
+	os->min_length = (int)min_length;
 
 	return os;
 }
@@ -328,7 +330,8 @@ void git_oid_shorten_free(git_oid_shorten *os)
  */
 int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 {
-	int i, is_leaf;
+	int i;
+	bool is_leaf;
 	node_index idx;
 
 	if (os->full)
@@ -338,7 +341,7 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 		return os->min_length;
 
 	idx = 0;
-	is_leaf = 0;
+	is_leaf = false;
 
 	for (i = 0; i < GIT_OID_HEXSZ; ++i) {
 		int c = git__fromhex(text_oid[i]);
@@ -368,11 +371,11 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 		}
 
 		idx = node->children[c];
-		is_leaf = 0;
+		is_leaf = false;
 
 		if (idx < 0) {
 			node->children[c] = idx = -idx;
-			is_leaf = 1;
+			is_leaf = true;
 		}
 	}
 
diff --git a/src/pack.c b/src/pack.c
index a4e506945..af8be255d 100644
--- a/src/pack.c
+++ b/src/pack.c
@@ -165,6 +165,7 @@ static int pack_index_open(struct git_pack_file *p)
 {
 	char *idx_name;
 	int error;
+	size_t name_len, offset;
 
 	if (p->index_map.data)
 		return 0;
@@ -172,7 +173,11 @@ static int pack_index_open(struct git_pack_file *p)
 	idx_name = git__strdup(p->pack_name);
 	GITERR_CHECK_ALLOC(idx_name);
 
-	strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
+	name_len = strlen(idx_name);
+	offset = name_len - strlen(".pack");
+	assert(offset < name_len); /* make sure no underflow */
+
+	strncpy(idx_name + offset, ".idx", name_len - offset);
 
 	error = pack_index_check(idx_name, p);
 	git__free(idx_name);
@@ -474,7 +479,7 @@ git_off_t get_delta_base(
  *
  ***********************************************************/
 
-static struct git_pack_file *packfile_alloc(int extra)
+static struct git_pack_file *packfile_alloc(size_t extra)
 {
 	struct git_pack_file *p = git__calloc(1, sizeof(*p) + extra);
 	if (p != NULL)
diff --git a/src/path.c b/src/path.c
index 3c1a723ea..a7cf4402f 100644
--- a/src/path.c
+++ b/src/path.c
@@ -464,21 +464,22 @@ int git_path_find_dir(git_buf *dir, const char *path, const char *base)
 	return error;
 }
 
-int git_path_cmp(const char *name1, int len1, int isdir1,
-		const char *name2, int len2, int isdir2)
+int git_path_cmp(
+	const char *name1, size_t len1, int isdir1,
+	const char *name2, size_t len2, int isdir2)
 {
-	int len = len1 < len2 ? len1 : len2;
+	size_t len = len1 < len2 ? len1 : len2;
 	int cmp;
 
 	cmp = memcmp(name1, name2, len);
 	if (cmp)
 		return cmp;
 	if (len1 < len2)
-		return ((!isdir1 && !isdir2) ? -1 :
-						(isdir1 ? '/' - name2[len1] : name2[len1] - '/'));
+		return (!isdir1 && !isdir2) ? -1 :
+			(isdir1 ? '/' - name2[len1] : name2[len1] - '/');
 	if (len1 > len2)
-		return ((!isdir1 && !isdir2) ? 1 :
-						(isdir2 ? name1[len2] - '/' : '/' - name1[len2]));
+		return (!isdir1 && !isdir2) ? 1 :
+			(isdir2 ? name1[len2] - '/' : '/' - name1[len2]);
 	return 0;
 }
 
diff --git a/src/path.h b/src/path.h
index eb397d17a..fd76805e5 100644
--- a/src/path.h
+++ b/src/path.h
@@ -204,8 +204,8 @@ extern int git_path_direach(
  * Sort function to order two paths.
  */
 extern int git_path_cmp(
-	const char *name1, int len1, int isdir1,
-	const char *name2, int len2, int isdir2);
+	const char *name1, size_t len1, int isdir1,
+	const char *name2, size_t len2, int isdir2);
 
 /**
  * Invoke callback up path directory by directory until the ceiling is
diff --git a/src/pkt.c b/src/pkt.c
index f8af7e235..ee113cd46 100644
--- a/src/pkt.c
+++ b/src/pkt.c
@@ -102,6 +102,7 @@ static int comment_pkt(git_pkt **out, const char *line, size_t len)
  */
 static int ref_pkt(git_pkt **out, const char *line, size_t len)
 {
+	int error;
 	git_pkt_ref *pkt;
 
 	pkt = git__malloc(sizeof(git_pkt_ref));
@@ -109,14 +110,13 @@ static int ref_pkt(git_pkt **out, const char *line, size_t len)
 
 	memset(pkt, 0x0, sizeof(git_pkt_ref));
 	pkt->type = GIT_PKT_REF;
-	if (git_oid_fromstr(&pkt->head.oid, line) < 0) {
-		giterr_set(GITERR_NET, "Error parsing pkt-line");
+	if ((error = git_oid_fromstr(&pkt->head.oid, line)) < 0)
 		goto error_out;
-	}
 
 	/* Check for a bit of consistency */
 	if (line[GIT_OID_HEXSZ] != ' ') {
 		giterr_set(GITERR_NET, "Error parsing pkt-line");
+		error = -1;
 		goto error_out;
 	}
 
@@ -138,30 +138,32 @@ static int ref_pkt(git_pkt **out, const char *line, size_t len)
 	}
 
 	*out = (git_pkt *)pkt;
-
 	return 0;
 
 error_out:
 	git__free(pkt);
-	return -1;
+	return error;
 }
 
-static int parse_len(const char *line)
+static int32_t parse_len(const char *line)
 {
 	char num[PKT_LEN_SIZE + 1];
-	int i, len;
+	int i, error;
+	int32_t len;
 	const char *num_end;
 
 	memcpy(num, line, PKT_LEN_SIZE);
 	num[PKT_LEN_SIZE] = '\0';
 
 	for (i = 0; i < PKT_LEN_SIZE; ++i) {
-		if (!isxdigit(num[i]))
-			return GIT_ENOTNUM;
+		if (!isxdigit(num[i])) {
+			giterr_set(GITERR_NET, "Found invalid hex digit in length");
+			return -1;
+		}
 	}
 
-	if (git__strtol32(&len, num, &num_end, 16) < 0)
-		return -1;
+	if ((error = git__strtol32(&len, num, &num_end, 16)) < 0)
+		return error;
 
 	return len;
 }
@@ -179,16 +181,20 @@ static int parse_len(const char *line)
  * in ASCII hexadecimal (including itself)
  */
 
-int git_pkt_parse_line(git_pkt **head, const char *line, const char **out, size_t bufflen)
+int git_pkt_parse_line(
+	git_pkt **head, const char *line, const char **out, size_t bufflen)
 {
-	int ret = 0;
-	size_t len;
+	int ret;
+	int32_t len;
 
 	/* Not even enough for the length */
-	if (bufflen > 0 && bufflen < PKT_LEN_SIZE)
-		return GIT_ESHORTBUFFER;
+	if (bufflen > 0 && bufflen < PKT_LEN_SIZE) {
+		giterr_set(GITERR_NET, "Insufficient buffer data");
+		return -1;
+	}
 
-	if ((ret = parse_len(line)) < 0) {
+	len = parse_len(line);
+	if (len < 0) {
 		/*
 		 * If we fail to parse the length, it might be because the
 		 * server is trying to send us the packfile already.
@@ -198,18 +204,17 @@ int git_pkt_parse_line(git_pkt **head, const char *line, const char **out, size_
 			return pack_pkt(head);
 		}
 
-		giterr_set(GITERR_NET, "Error parsing pkt-line");
-		return -1;
+		return (int)len;
 	}
 
-	len = ret;
-
 	/*
 	 * If we were given a buffer length, then make sure there is
 	 * enough in the buffer to satisfy this line
 	 */
-	if (bufflen > 0 && bufflen < len)
-		return GIT_ESHORTBUFFER;
+	if (bufflen > 0 && bufflen < (size_t)len) {
+		giterr_set(GITERR_NET, "Insufficient buffer data for packet length");
+		return -1;
+	}
 
 	line += PKT_LEN_SIZE;
 	/*
@@ -245,7 +250,7 @@ int git_pkt_parse_line(git_pkt **head, const char *line, const char **out, size_
 
 void git_pkt_free(git_pkt *pkt)
 {
-	if(pkt->type == GIT_PKT_REF) {
+	if (pkt->type == GIT_PKT_REF) {
 		git_pkt_ref *p = (git_pkt_ref *) pkt;
 		git__free(p->head.name);
 	}
@@ -258,7 +263,7 @@ int git_pkt_buffer_flush(git_buf *buf)
 	return git_buf_put(buf, pkt_flush_str, strlen(pkt_flush_str));
 }
 
-int git_pkt_send_flush(int s)
+int git_pkt_send_flush(GIT_SOCKET s)
 {
 
 	return gitno_send(s, pkt_flush_str, strlen(pkt_flush_str), 0);
@@ -268,12 +273,14 @@ static int buffer_want_with_caps(git_remote_head *head, git_transport_caps *caps
 {
 	char capstr[20];
 	char oid[GIT_OID_HEXSZ +1] = {0};
-	int len;
+	unsigned int len;
 
 	if (caps->ofs_delta)
-		strcpy(capstr, GIT_CAP_OFS_DELTA);
+		strncpy(capstr, GIT_CAP_OFS_DELTA, sizeof(capstr));
 
-	len = strlen("XXXXwant ") + GIT_OID_HEXSZ + 1 /* NUL */ + strlen(capstr) + 1 /* LF */;
+	len = (unsigned int)
+		(strlen("XXXXwant ") + GIT_OID_HEXSZ + 1 /* NUL */ +
+		 strlen(capstr) + 1 /* LF */);
 	git_buf_grow(buf, buf->size + len);
 
 	git_oid_fmt(oid, &head->oid);
@@ -283,15 +290,14 @@ static int buffer_want_with_caps(git_remote_head *head, git_transport_caps *caps
 static int send_want_with_caps(git_remote_head *head, git_transport_caps *caps, GIT_SOCKET fd)
 {
 	git_buf buf = GIT_BUF_INIT;
-	int error;
+	int ret;
 
 	if (buffer_want_with_caps(head, caps, &buf) < 0)
 		return -1;
 
-	error = gitno_send(fd, buf.ptr, buf.size, 0);
+	ret = gitno_send(fd, buf.ptr, buf.size, 0);
 	git_buf_free(&buf);
-
-	return error;
+	return ret;
 }
 
 /*
@@ -335,7 +341,7 @@ int git_pkt_buffer_wants(const git_vector *refs, git_transport_caps *caps, git_b
 	return git_pkt_buffer_flush(buf);
 }
 
-int git_pkt_send_wants(const git_vector *refs, git_transport_caps *caps, int fd)
+int git_pkt_send_wants(const git_vector *refs, git_transport_caps *caps, GIT_SOCKET fd)
 {
 	unsigned int i = 0;
 	char buf[sizeof(pkt_want_prefix) + GIT_OID_HEXSZ + 1];
@@ -357,6 +363,7 @@ int git_pkt_send_wants(const git_vector *refs, git_transport_caps *caps, int fd)
 
 		if (send_want_with_caps(refs->contents[i], caps, fd) < 0)
 			return -1;
+
 		/* Increase it here so it's correct whether we run this or not */
 		i++;
 	}
@@ -384,7 +391,7 @@ int git_pkt_buffer_have(git_oid *oid, git_buf *buf)
 	return git_buf_printf(buf, "%s%s\n", pkt_have_prefix, oidhex);
 }
 
-int git_pkt_send_have(git_oid *oid, int fd)
+int git_pkt_send_have(git_oid *oid, GIT_SOCKET fd)
 {
 	char buf[] = "0032have 0000000000000000000000000000000000000000\n";
 
@@ -398,7 +405,7 @@ int git_pkt_buffer_done(git_buf *buf)
 	return git_buf_puts(buf, pkt_done_str);
 }
 
-int git_pkt_send_done(int fd)
+int git_pkt_send_done(GIT_SOCKET fd)
 {
 	return gitno_send(fd, pkt_done_str, strlen(pkt_done_str), 0);
 }
diff --git a/src/pkt.h b/src/pkt.h
index b0bc0892e..1f8d62e1a 100644
--- a/src/pkt.h
+++ b/src/pkt.h
@@ -11,6 +11,7 @@
 #include "common.h"
 #include "transport.h"
 #include "buffer.h"
+#include "posix.h"
 #include "git2/net.h"
 
 enum git_pkt_type {
@@ -65,13 +66,13 @@ typedef struct {
 
 int git_pkt_parse_line(git_pkt **head, const char *line, const char **out, size_t len);
 int git_pkt_buffer_flush(git_buf *buf);
-int git_pkt_send_flush(int s);
+int git_pkt_send_flush(GIT_SOCKET s);
 int git_pkt_buffer_done(git_buf *buf);
-int git_pkt_send_done(int s);
+int git_pkt_send_done(GIT_SOCKET s);
 int git_pkt_buffer_wants(const git_vector *refs, git_transport_caps *caps, git_buf *buf);
-int git_pkt_send_wants(const git_vector *refs, git_transport_caps *caps, int fd);
+int git_pkt_send_wants(const git_vector *refs, git_transport_caps *caps, GIT_SOCKET fd);
 int git_pkt_buffer_have(git_oid *oid, git_buf *buf);
-int git_pkt_send_have(git_oid *oid, int fd);
+int git_pkt_send_have(git_oid *oid, GIT_SOCKET fd);
 void git_pkt_free(git_pkt *pkt);
 
 #endif
diff --git a/src/posix.c b/src/posix.c
index 977880999..a3f81d767 100644
--- a/src/posix.c
+++ b/src/posix.c
@@ -58,7 +58,13 @@ int p_read(git_file fd, void *buf, size_t cnt)
 {
 	char *b = buf;
 	while (cnt) {
-		ssize_t r = read(fd, b, cnt);
+		ssize_t r;
+#ifdef GIT_WIN32
+		assert((size_t)((unsigned int)cnt) == cnt);
+		r = read(fd, b, (unsigned int)cnt);
+#else
+		r = read(fd, b, cnt);
+#endif
 		if (r < 0) {
 			if (errno == EINTR || errno == EAGAIN)
 				continue;
@@ -76,7 +82,13 @@ int p_write(git_file fd, const void *buf, size_t cnt)
 {
 	const char *b = buf;
 	while (cnt) {
-		ssize_t r = write(fd, b, cnt);
+		ssize_t r;
+#ifdef GIT_WIN32
+		assert((size_t)((unsigned int)cnt) == cnt);
+		r = write(fd, b, (unsigned int)cnt);
+#else
+		r = write(fd, b, cnt);
+#endif
 		if (r < 0) {
 			if (errno == EINTR || errno == EAGAIN)
 				continue;
diff --git a/src/posix.h b/src/posix.h
index fb17cba6c..752d5156f 100644
--- a/src/posix.h
+++ b/src/posix.h
@@ -54,6 +54,14 @@ extern int p_rename(const char *from, const char *to);
 #define p_rmdir(p) rmdir(p)
 #define p_chmod(p,m) chmod(p, m)
 #define p_access(p,m) access(p,m)
+#define p_recv(s,b,l,f) recv(s,b,l,f)
+#define p_send(s,b,l,f) send(s,b,l,f)
+typedef int GIT_SOCKET;
+#define INVALID_SOCKET -1
+
+#else
+
+typedef SOCKET GIT_SOCKET;
 
 #endif
 
diff --git a/src/pqueue.c b/src/pqueue.c
index 3fbf93315..cb59c13ec 100644
--- a/src/pqueue.c
+++ b/src/pqueue.c
@@ -17,14 +17,14 @@ int git_pqueue_init(git_pqueue *q, size_t n, git_pqueue_cmp cmppri)
 	assert(q);
 
 	/* Need to allocate n+1 elements since element 0 isn't used. */
-	if ((q->d = git__malloc((n + 1) * sizeof(void *))) == NULL)
-		return GIT_ENOMEM;
+	q->d = git__malloc((n + 1) * sizeof(void *));
+	GITERR_CHECK_ALLOC(q->d);
 
 	q->size = 1;
 	q->avail = q->step = (n + 1); /* see comment above about n+1 */
 	q->cmppri = cmppri;
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 
@@ -102,8 +102,8 @@ int git_pqueue_insert(git_pqueue *q, void *d)
 	/* allocate more memory if necessary */
 	if (q->size >= q->avail) {
 		newsize = q->size + q->step;
-		if ((tmp = git__realloc(q->d, sizeof(void *) * newsize)) == NULL)
-			return GIT_ENOMEM;
+		tmp = git__realloc(q->d, sizeof(void *) * newsize);
+		GITERR_CHECK_ALLOC(tmp);
 
 		q->d = tmp;
 		q->avail = newsize;
@@ -114,7 +114,7 @@ int git_pqueue_insert(git_pqueue *q, void *d)
 	q->d[i] = d;
 	bubble_up(q, i);
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 
diff --git a/src/refs.c b/src/refs.c
index 90cb920ee..6fffe3e6f 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -133,13 +133,13 @@ static int reference_read(
 
 static int loose_parse_symbolic(git_reference *ref, git_buf *file_content)
 {
-	const unsigned int header_len = strlen(GIT_SYMREF);
+	const unsigned int header_len = (unsigned int)strlen(GIT_SYMREF);
 	const char *refname_start;
 	char *eol;
 
 	refname_start = (const char *)file_content->ptr;
 
-	if (file_content->size < (header_len + 1))
+	if (file_content->size < header_len + 1)
 		goto corrupt;
 
 	/*
@@ -730,11 +730,11 @@ static int packed_write(git_repository *repo)
 	unsigned int i;
 	git_buf pack_file_path = GIT_BUF_INIT;
 	git_vector packing_list;
-	size_t total_refs;
+	unsigned int total_refs;
 
 	assert(repo && repo->references.packfile);
 
-	total_refs = repo->references.packfile->key_count;
+	total_refs = (unsigned int)repo->references.packfile->key_count;
 
 	if (git_vector_init(&packing_list, total_refs, packed_sort) < 0)
 		return -1;
@@ -821,9 +821,9 @@ static int _reference_available_cb(const char *ref, void *data)
 	d = (struct reference_available_t *)data;
 
 	if (!d->old_ref || strcmp(d->old_ref, ref)) {
-		int reflen = strlen(ref);
-		int newlen = strlen(d->new_ref);
-		int cmplen = reflen < newlen ? reflen : newlen;
+		size_t reflen = strlen(ref);
+		size_t newlen = strlen(d->new_ref);
+		size_t cmplen = reflen < newlen ? reflen : newlen;
 		const char *lead = reflen < newlen ? d->new_ref : ref;
 
 		if (!strncmp(d->new_ref, ref, cmplen) && lead[cmplen] == '/') {
diff --git a/src/repository.c b/src/repository.c
index 572b51622..d191c78d5 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -183,21 +183,20 @@ static int find_ceiling_dir_offset(
 	char buf[GIT_PATH_MAX + 1];
 	char buf2[GIT_PATH_MAX + 1];
 	const char *ceil, *sep;
-	int len, max_len = -1;
-	int min_len;
+	size_t len, max_len = 0, min_len;
 
 	assert(path);
 
-	min_len = git_path_root(path) + 1;
+	min_len = (size_t)(git_path_root(path) + 1);
 
 	if (ceiling_directories == NULL || min_len == 0)
-		return min_len;
+		return (int)min_len;
 
 	for (sep = ceil = ceiling_directories; *sep; ceil = sep + 1) {
 		for (sep = ceil; *sep && *sep != GIT_PATH_LIST_SEPARATOR; sep++);
 		len = sep - ceil;
 
-		if (len == 0 || len >= (int)sizeof(buf) || git_path_root(ceil) == -1)
+		if (len == 0 || len >= sizeof(buf) || git_path_root(ceil) == -1)
 			continue;
 
 		strncpy(buf, ceil, len);
@@ -218,7 +217,7 @@ static int find_ceiling_dir_offset(
 		}
 	}
 
-	return max_len <= min_len ? min_len : max_len;
+	return (int)(max_len <= min_len ? min_len : max_len);
 }
 
 /*
diff --git a/src/revwalk.c b/src/revwalk.c
index 2d815b96a..a88fc84c4 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -77,11 +77,10 @@ static int commit_time_cmp(void *a, void *b)
 static commit_list *commit_list_insert(commit_object *item, commit_list **list_p)
 {
 	commit_list *new_list = git__malloc(sizeof(commit_list));
-	if (new_list == NULL)
-		return NULL;
-
-	new_list->item = item;
-	new_list->next = *list_p;
+	if (new_list != NULL) {
+		new_list->item = item;
+		new_list->next = *list_p;
+	}
 	*list_p = new_list;
 	return new_list;
 }
@@ -143,8 +142,7 @@ static int alloc_chunk(git_revwalk *walk)
 	void *chunk;
 
 	chunk = git__calloc(COMMITS_PER_CHUNK, CHUNK_STEP);
-	if (chunk == NULL)
-		return GIT_ENOMEM;
+	GITERR_CHECK_ALLOC(chunk);
 
 	walk->chunk_size = 0;
 	return git_vector_insert(&walk->memory_alloc, chunk);
@@ -155,7 +153,8 @@ static commit_object *alloc_commit(git_revwalk *walk)
 	unsigned char *chunk;
 
 	if (walk->chunk_size == COMMITS_PER_CHUNK)
-		alloc_chunk(walk);
+		if (alloc_chunk(walk) < 0)
+			return NULL;
 
 	chunk = git_vector_get(&walk->memory_alloc, walk->memory_alloc.length - 1);
 	chunk += (walk->chunk_size * CHUNK_STEP);
@@ -186,7 +185,7 @@ static commit_object *commit_lookup(git_revwalk *walk, const git_oid *oid)
 
 	git_oid_cpy(&commit->oid, oid);
 
-	if (git_hashtable_insert(walk->commits, &commit->oid, commit) < GIT_SUCCESS) {
+	if (git_hashtable_insert(walk->commits, &commit->oid, commit) < 0) {
 		git__free(commit);
 		return NULL;
 	}
@@ -196,7 +195,7 @@ static commit_object *commit_lookup(git_revwalk *walk, const git_oid *oid)
 
 static int commit_quick_parse(git_revwalk *walk, commit_object *commit, git_rawobj *raw)
 {
-	const int parent_len = strlen("parent ") + GIT_OID_HEXSZ + 1;
+	const size_t parent_len = strlen("parent ") + GIT_OID_HEXSZ + 1;
 
 	unsigned char *buffer = raw->data;
 	unsigned char *buffer_end = buffer + raw->len;
@@ -262,7 +261,7 @@ static int commit_parse(git_revwalk *walk, commit_object *commit)
 		return 0;
 
 	if ((error = git_odb_read(&obj, walk->odb, &commit->oid)) < 0)
-		return -1;
+		return error;
 
 	if (obj->raw.type != GIT_OBJ_COMMIT) {
 		git_odb_object_free(obj);
@@ -432,6 +431,8 @@ static void mark_uninteresting(commit_object *commit)
 
 static int process_commit(git_revwalk *walk, commit_object *commit, int hide)
 {
+	int error;
+
 	if (hide)
 		mark_uninteresting(commit);
 
@@ -440,8 +441,8 @@ static int process_commit(git_revwalk *walk, commit_object *commit, int hide)
 
 	commit->seen = 1;
 
-	if (commit_parse(walk, commit) < 0)
-		return -1;
+	if ((error = commit_parse(walk, commit)) < 0)
+		return error;
 
 	return walk->enqueue(walk, commit);
 }
@@ -449,13 +450,12 @@ static int process_commit(git_revwalk *walk, commit_object *commit, int hide)
 static int process_commit_parents(git_revwalk *walk, commit_object *commit)
 {
 	unsigned short i;
+	int error = 0;
 
-	for (i = 0; i < commit->out_degree; ++i) {
-		if (process_commit(walk, commit->parents[i], commit->uninteresting) < 0)
-			return -1;
-	}
+	for (i = 0; i < commit->out_degree && !error; ++i)
+		error = process_commit(walk, commit->parents[i], commit->uninteresting);
 
-	return 0;
+	return error;
 }
 
 static int push_commit(git_revwalk *walk, const git_oid *oid, int uninteresting)
@@ -464,7 +464,7 @@ static int push_commit(git_revwalk *walk, const git_oid *oid, int uninteresting)
 
 	commit = commit_lookup(walk, oid);
 	if (commit == NULL)
-		return -1;
+		return -1; /* error already reported by failed lookup */
 
 	commit->uninteresting = uninteresting;
 	if (walk->one == NULL && !uninteresting) {
@@ -549,7 +549,8 @@ static int push_glob(git_revwalk *walk, const char *glob, int hide)
 	data.glob = git_buf_cstr(&buf);
 	data.hide = hide;
 
-	if (git_reference_foreach(walk->repo, GIT_REF_LISTALL, push_glob_cb, &data) < 0)
+	if (git_reference_foreach(
+			walk->repo, GIT_REF_LISTALL, push_glob_cb, &data) < 0)
 		goto on_error;
 
 	regfree(&preg);
@@ -605,7 +606,7 @@ static int revwalk_enqueue_timesort(git_revwalk *walk, commit_object *commit)
 
 static int revwalk_enqueue_unsorted(git_revwalk *walk, commit_object *commit)
 {
-	return commit_list_insert(commit, &walk->iterator_rand) ? GIT_SUCCESS : GIT_ENOMEM;
+	return commit_list_insert(commit, &walk->iterator_rand) ? 0 : -1;
 }
 
 static int revwalk_next_timesort(commit_object **object_out, git_revwalk *walk)
@@ -615,7 +616,7 @@ static int revwalk_next_timesort(commit_object **object_out, git_revwalk *walk)
 
 	while ((next = git_pqueue_pop(&walk->iterator_time)) != NULL) {
 		if ((error = process_commit_parents(walk, next)) < 0)
-			return -1;
+			return error;
 
 		if (!next->uninteresting) {
 			*object_out = next;
@@ -633,7 +634,7 @@ static int revwalk_next_unsorted(commit_object **object_out, git_revwalk *walk)
 
 	while ((next = commit_list_pop(&walk->iterator_rand)) != NULL) {
 		if ((error = process_commit_parents(walk, next)) < 0)
-			return -1;
+			return error;
 
 		if (!next->uninteresting) {
 			*object_out = next;
@@ -715,19 +716,19 @@ static int prepare_walk(git_revwalk *walk)
 		}
 
 		if (error != GIT_EREVWALKOVER)
-			return -1;
+			return error;
 
 		walk->get_next = &revwalk_next_toposort;
 	}
 
 	if (walk->sorting & GIT_SORT_REVERSE) {
 
-		while ((error = walk->get_next(&next, walk)) == GIT_SUCCESS)
+		while ((error = walk->get_next(&next, walk)) == 0)
 			if (commit_list_insert(next, &walk->iterator_reverse) == NULL)
 				return -1;
 
 		if (error != GIT_EREVWALKOVER)
-			return -1;
+			return error;
 
 		walk->get_next = &revwalk_next_reverse;
 	}
@@ -752,16 +753,13 @@ int git_revwalk_new(git_revwalk **revwalk_out, git_repository *repo)
 	walk->commits = git_hashtable_alloc(64,
 			object_table_hash,
 			(git_hash_keyeq_ptr)git_oid_cmp);
+	GITERR_CHECK_ALLOC(walk->commits);
 
-	if (walk->commits == NULL) {
-		git__free(walk);
+	if (git_pqueue_init(&walk->iterator_time, 8, commit_time_cmp) < 0 ||
+		git_vector_init(&walk->memory_alloc, 8, NULL) < 0 ||
+		git_vector_init(&walk->twos, 4, NULL) < 0 ||
+		alloc_chunk(walk) < 0)
 		return -1;
-	}
-
-	git_pqueue_init(&walk->iterator_time, 8, commit_time_cmp);
-	git_vector_init(&walk->memory_alloc, 8, NULL);
-	git_vector_init(&walk->twos, 4, NULL);
-	alloc_chunk(walk);
 
 	walk->get_next = &revwalk_next_unsorted;
 	walk->enqueue = &revwalk_enqueue_unsorted;
@@ -840,7 +838,7 @@ int git_revwalk_next(git_oid *oid, git_revwalk *walk)
 
 	if (!walk->walking) {
 		if ((error = prepare_walk(walk)) < 0)
-			return -1;
+			return error;
 	}
 
 	error = walk->get_next(&next, walk);
@@ -850,11 +848,10 @@ int git_revwalk_next(git_oid *oid, git_revwalk *walk)
 		return GIT_EREVWALKOVER;
 	}
 
-	if (error < 0)
-		return -1;
+	if (!error)
+		git_oid_cpy(oid, &next->oid);
 
-	git_oid_cpy(oid, &next->oid);
-	return 0;
+	return error;
 }
 
 void git_revwalk_reset(git_revwalk *walk)
diff --git a/src/sha1.c b/src/sha1.c
index af3c2d2d0..8aaedeb8f 100644
--- a/src/sha1.c
+++ b/src/sha1.c
@@ -232,7 +232,7 @@ void git__blk_SHA1_Init(blk_SHA_CTX *ctx)
 	ctx->H[4] = 0xc3d2e1f0;
 }
 
-void git__blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
+void git__blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, size_t len)
 {
 	unsigned int lenW = ctx->size & 63;
 
@@ -242,7 +242,7 @@ void git__blk_SHA1_Update(blk_SHA_CTX *ctx, const void *data, unsigned long len)
 	if (lenW) {
 		unsigned int left = 64 - lenW;
 		if (len < left)
-			left = len;
+			left = (unsigned int)len;
 		memcpy(lenW + (char *)ctx->W, data, left);
 		lenW = (lenW + left) & 63;
 		len -= left;
diff --git a/src/sha1.h b/src/sha1.h
index 117e93106..93a244d76 100644
--- a/src/sha1.h
+++ b/src/sha1.h
@@ -12,7 +12,7 @@ typedef struct {
 } blk_SHA_CTX;
 
 void git__blk_SHA1_Init(blk_SHA_CTX *ctx);
-void git__blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, unsigned long len);
+void git__blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, size_t len);
 void git__blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx);
 
 #define SHA_CTX		blk_SHA_CTX
diff --git a/src/signature.c b/src/signature.c
index 87386bc62..4d6d11c70 100644
--- a/src/signature.c
+++ b/src/signature.c
@@ -47,7 +47,7 @@ static int signature_error(const char *msg)
 static int process_trimming(const char *input, char **storage, const char *input_end, int fail_when_empty)
 {
 	const char *left, *right;
-	int trimmed_input_length;
+	size_t trimmed_input_length;
 
 	assert(storage);
 
diff --git a/src/tag.c b/src/tag.c
index cfd2c7081..552487986 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -67,7 +67,8 @@ int git_tag__parse_buffer(git_tag *tag, const char *buffer, size_t length)
 		NULL, "commit\n", "tree\n", "blob\n", "tag\n"
 	};
 
-	unsigned int i, text_len;
+	unsigned int i;
+	size_t text_len;
 	char *search;
 	int error;
 
diff --git a/src/transports/git.c b/src/transports/git.c
index fd3ff5b32..825f072c8 100644
--- a/src/transports/git.c
+++ b/src/transports/git.c
@@ -46,7 +46,7 @@ static int gen_proto(git_buf *request, const char *cmd, const char *url)
 	char *delim, *repo;
 	char default_command[] = "git-upload-pack";
 	char host[] = "host=";
-	int len;
+	size_t len;
 
 	delim = strchr(url, '/');
 	if (delim == NULL) {
@@ -66,7 +66,8 @@ static int gen_proto(git_buf *request, const char *cmd, const char *url)
 	len = 4 + strlen(cmd) + 1 + strlen(repo) + 1 + strlen(host) + (delim - url) + 1;
 
 	git_buf_grow(request, len);
-	git_buf_printf(request, "%04x%s %s%c%s", len, cmd, repo, 0, host);
+	git_buf_printf(request, "%04x%s %s%c%s",
+		(unsigned int)(len & 0x0FFFF), cmd, repo, 0, host);
 	git_buf_put(request, url, delim - url);
 	git_buf_putc(request, '\0');
 
@@ -119,7 +120,7 @@ static int do_connect(transport_git *t, const char *url)
 	git__free(port);
 
 	if (error < GIT_SUCCESS && s > 0)
-		close(s);
+		gitno_close(s);
 	if (!connected) {
 		giterr_set(GITERR_NET, "Failed to connect to the host");
 		return -1;
diff --git a/src/transports/http.c b/src/transports/http.c
index d8af99dbf..0938fefff 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -32,7 +32,7 @@ typedef struct {
 	git_protocol proto;
 	git_vector refs;
 	git_vector common;
-	int socket;
+	GIT_SOCKET socket;
 	git_buf buf;
 	git_remote_head **heads;
 	int error;
@@ -96,7 +96,7 @@ static int do_connect(transport_http *t, const char *host, const char *port)
 	t->socket = s;
 	t->parent.connected = 1;
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 /*
diff --git a/src/tree.c b/src/tree.c
index 5957f7a61..56a722960 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -624,7 +624,7 @@ static int tree_frompath(
 	git_tree **parent_out,
 	git_tree *root,
 	git_buf *treeentry_path,
-	int offset)
+	size_t offset)
 {
 	char *slash_pos = NULL;
 	const git_tree_entry* entry;
diff --git a/src/tsort.c b/src/tsort.c
index 6fbec5b2a..f54c21e50 100644
--- a/src/tsort.c
+++ b/src/tsort.c
@@ -30,8 +30,10 @@ static int binsearch(void **dst, const void *x, size_t size, cmp_ptr_t cmp)
 	int l, c, r;
 	void *lx, *cx;
 
+	assert(size > 0);
+
 	l = 0;
-	r = size - 1;
+	r = (int)size - 1;
 	c = r >> 1;
 	lx = dst[l];
 
@@ -84,7 +86,7 @@ static void bisort(void **dst, size_t start, size_t size, cmp_ptr_t cmp)
 		/* Else we need to find the right place, shift everything over, and squeeze in */
 		x = dst[i];
 		location = binsearch(dst, x, i, cmp);
-		for (j = i - 1; j >= location; j--) {
+		for (j = (int)i - 1; j >= location; j--) {
 			dst[j + 1] = dst[j];
 		}
 		dst[location] = x;
@@ -104,7 +106,7 @@ struct tsort_store {
 	void **storage;
 };
 
-static void reverse_elements(void **dst, int start, int end)
+static void reverse_elements(void **dst, ssize_t start, ssize_t end)
 {
 	while (start < end) {
 		void *tmp = dst[start];
@@ -116,7 +118,7 @@ static void reverse_elements(void **dst, int start, int end)
 	}
 }
 
-static int count_run(void **dst, ssize_t start, ssize_t size, struct tsort_store *store)
+static ssize_t count_run(void **dst, ssize_t start, ssize_t size, struct tsort_store *store)
 {
 	ssize_t curr = start + 2;
 
@@ -148,7 +150,7 @@ static int count_run(void **dst, ssize_t start, ssize_t size, struct tsort_store
 	}
 }
 
-static int compute_minrun(size_t n)
+static size_t compute_minrun(size_t n)
 {
 	int r = 0;
 	while (n >= 64) {
@@ -158,19 +160,19 @@ static int compute_minrun(size_t n)
 	return n + r;
 }
 
-static int check_invariant(struct tsort_run *stack, int stack_curr)
+static int check_invariant(struct tsort_run *stack, ssize_t stack_curr)
 {
 	if (stack_curr < 2)
 		return 1;
 
 	else if (stack_curr == 2) {
-		const int A = stack[stack_curr - 2].length;
-		const int B = stack[stack_curr - 1].length;
+		const ssize_t A = stack[stack_curr - 2].length;
+		const ssize_t B = stack[stack_curr - 1].length;
 		return (A > B);
 	} else {
-		const int A = stack[stack_curr - 3].length;
-		const int B = stack[stack_curr - 2].length;
-		const int C = stack[stack_curr - 1].length;
+		const ssize_t A = stack[stack_curr - 3].length;
+		const ssize_t B = stack[stack_curr - 2].length;
+		const ssize_t C = stack[stack_curr - 1].length;
 		return !((A <= B + C) || (B <= C));
 	}
 }
@@ -195,7 +197,7 @@ static int resize(struct tsort_store *store, size_t new_size)
 	return 0;
 }
 
-static void merge(void **dst, const struct tsort_run *stack, int stack_curr, struct tsort_store *store)
+static void merge(void **dst, const struct tsort_run *stack, ssize_t stack_curr, struct tsort_store *store)
 {
 	const ssize_t A = stack[stack_curr - 2].length;
 	const ssize_t B = stack[stack_curr - 1].length;
@@ -343,7 +345,7 @@ void git__tsort(void **dst, size_t size, cmp_ptr_t cmp)
 	}
 
 	/* compute the minimum run length */
-	minrun = compute_minrun(size);
+	minrun = (ssize_t)compute_minrun(size);
 
 	/* temporary storage for merges */
 	store->alloc = 0;
diff --git a/src/util.c b/src/util.c
index 81ad10609..2cf7b158b 100644
--- a/src/util.c
+++ b/src/util.c
@@ -391,10 +391,11 @@ int git__bsearch(
 	int (*compare)(const void *, const void *),
 	size_t *position)
 {
-	int lim, cmp = -1;
+	unsigned int lim;
+	int cmp = -1;
 	void **part, **base = array;
 
-	for (lim = array_len; lim != 0; lim >>= 1) {
+	for (lim = (unsigned int)array_len; lim != 0; lim >>= 1) {
 		part = base + (lim >> 1);
 		cmp = (*compare)(key, *part);
 		if (cmp == 0) {
diff --git a/src/vector.c b/src/vector.c
index d73c2b418..304f324f0 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -10,7 +10,7 @@
 #include "vector.h"
 
 static const double resize_factor = 1.75;
-static const size_t minimum_size = 8;
+static const unsigned int minimum_size = 8;
 
 static int resize_vector(git_vector *v)
 {
diff --git a/src/win32/posix.h b/src/win32/posix.h
index 60adc9666..d13d3e39b 100644
--- a/src/win32/posix.h
+++ b/src/win32/posix.h
@@ -49,5 +49,7 @@ extern int p_open(const char *path, int flags);
 extern int p_creat(const char *path, mode_t mode);
 extern int p_getcwd(char *buffer_out, size_t size);
 extern int p_rename(const char *from, const char *to);
+extern int p_recv(GIT_SOCKET socket, void *buffer, size_t length, int flags);
+extern int p_send(GIT_SOCKET socket, const void *buffer, size_t length, int flags);
 
 #endif
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index c6b36a847..8af664165 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -4,7 +4,7 @@
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
  */
-#include "posix.h"
+#include "../posix.h"
 #include "path.h"
 #include "utf-conv.h"
 #include <errno.h>
@@ -179,11 +179,11 @@ int p_readlink(const char *link, char *target, size_t target_len)
 	target_w = (wchar_t*)git__malloc(target_len * sizeof(wchar_t));
 	GITERR_CHECK_ALLOC(target_w);
 
-	dwRet = pGetFinalPath(hFile, target_w, target_len, 0x0);
+	dwRet = pGetFinalPath(hFile, target_w, (DWORD)target_len, 0x0);
 	if (dwRet == 0 ||
 		dwRet >= target_len ||
 		!WideCharToMultiByte(CP_UTF8, 0, target_w, -1, target,
-			target_len * sizeof(char), NULL, NULL))
+			(int)(target_len * sizeof(char)), NULL, NULL))
 		error = -1;
 
 	git__free(target_w);
@@ -241,13 +241,19 @@ int p_creat(const char *path, mode_t mode)
 
 int p_getcwd(char *buffer_out, size_t size)
 {
-	wchar_t* buf = (wchar_t*)git__malloc(sizeof(wchar_t) * (int)size);
 	int ret;
+	wchar_t* buf;
+
+	if ((size_t)((int)size) != size)
+		return -1;
+
+	buf = (wchar_t*)git__malloc(sizeof(wchar_t) * (int)size);
+	GITERR_CHECK_ALLOC(buf);
 
 	_wgetcwd(buf, (int)size);
 
 	ret = WideCharToMultiByte(
-		CP_UTF8, 0, buf, -1, buffer_out, size, NULL, NULL);
+		CP_UTF8, 0, buf, -1, buffer_out, (int)size, NULL, NULL);
 
 	git__free(buf);
 	return !ret ? -1 : 0;
@@ -421,3 +427,19 @@ int p_rename(const char *from, const char *to)
 
 	return ret;
 }
+
+int p_recv(GIT_SOCKET socket, void *buffer, size_t length, int flags)
+{
+	if ((size_t)((int)length) != length)
+		return -1; /* giterr_set will be done by caller */
+
+	return recv(socket, buffer, (int)length, flags);
+}
+
+int p_send(GIT_SOCKET socket, const void *buffer, size_t length, int flags)
+{
+	if ((size_t)((int)length) != length)
+		return -1; /* giterr_set will be done by caller */
+
+	return send(socket, buffer, (int)length, flags);
+}
diff --git a/src/win32/utf-conv.c b/src/win32/utf-conv.c
index f00f5be92..fbcb69d0a 100644
--- a/src/win32/utf-conv.c
+++ b/src/win32/utf-conv.c
@@ -31,27 +31,23 @@ void gitwin_set_utf8(void)
 wchar_t* gitwin_to_utf16(const char* str)
 {
 	wchar_t* ret;
-	int cb;
+	size_t cb;
 
 	if (!str)
 		return NULL;
 
 	cb = strlen(str) * sizeof(wchar_t);
-	if (cb == 0) {
-		ret = (wchar_t*)git__malloc(sizeof(wchar_t));
-		if (ret)
-			ret[0] = 0;
-		return ret;
-	}
+	if (cb == 0)
+		return (wchar_t *)git__calloc(1, sizeof(wchar_t));
 
 	/* Add space for null terminator */
 	cb += sizeof(wchar_t);
 
-	ret = (wchar_t*)git__malloc(cb);
+	ret = (wchar_t *)git__malloc(cb);
 	if (!ret)
 		return NULL;
 
-	if (MultiByteToWideChar(_active_codepage, 0, str, -1, ret, cb) == 0) {
+	if (MultiByteToWideChar(_active_codepage, 0, str, -1, ret, (int)cb) == 0) {
 		giterr_set(GITERR_OS, "Could not convert string to UTF-16");
 		git__free(ret);
 		ret = NULL;
@@ -62,7 +58,7 @@ wchar_t* gitwin_to_utf16(const char* str)
 
 int gitwin_append_utf16(wchar_t *buffer, const char *str, size_t len)
 {
-	int result = MultiByteToWideChar(_active_codepage, 0, str, -1, buffer, len);
+	int result = MultiByteToWideChar(_active_codepage, 0, str, -1, buffer, (int)len);
 	if (result == 0)
 		giterr_set(GITERR_OS, "Could not convert string to UTF-16");
 	return result;
@@ -71,19 +67,14 @@ int gitwin_append_utf16(wchar_t *buffer, const char *str, size_t len)
 char* gitwin_from_utf16(const wchar_t* str)
 {
 	char* ret;
-	int cb;
+	size_t cb;
 
-	if (!str) {
+	if (!str)
 		return NULL;
-	}
 
 	cb = wcslen(str) * sizeof(char);
-	if (cb == 0) {
-		ret = (char*)git__malloc(sizeof(char));
-		if (ret)
-			ret[0] = 0;
-		return ret;
-	}
+	if (cb == 0)
+		return (char *)git__calloc(1, sizeof(char));
 
 	/* Add space for null terminator */
 	cb += sizeof(char);
@@ -92,7 +83,7 @@ char* gitwin_from_utf16(const wchar_t* str)
 	if (!ret)
 		return NULL;
 
-	if (WideCharToMultiByte(_active_codepage, 0, str, -1, ret, cb, NULL, NULL) == 0) {
+	if (WideCharToMultiByte(_active_codepage, 0, str, -1, ret, (int)cb, NULL, NULL) == 0) {
 		giterr_set(GITERR_OS, "Could not convert string to UTF-8");
 		git__free(ret);
 		ret = NULL;
diff --git a/src/xdiff/xemit.c b/src/xdiff/xemit.c
index 8b7d417a1..e3e63d902 100644
--- a/src/xdiff/xemit.c
+++ b/src/xdiff/xemit.c
@@ -40,7 +40,7 @@ static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
 
 
 static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
-	long size, psize = strlen(pre);
+	long size, psize = (long)strlen(pre);
 	char const *rec;
 
 	size = xdl_get_rec(xdf, ri, &rec);
diff --git a/src/xdiff/xmerge.c b/src/xdiff/xmerge.c
index 9e13b25ab..84e424672 100644
--- a/src/xdiff/xmerge.c
+++ b/src/xdiff/xmerge.c
@@ -149,9 +149,9 @@ static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
 			      int size, int i, int style,
 			      xdmerge_t *m, char *dest, int marker_size)
 {
-	int marker1_size = (name1 ? strlen(name1) + 1 : 0);
-	int marker2_size = (name2 ? strlen(name2) + 1 : 0);
-	int marker3_size = (name3 ? strlen(name3) + 1 : 0);
+	int marker1_size = (name1 ? (int)strlen(name1) + 1 : 0);
+	int marker2_size = (name2 ? (int)strlen(name2) + 1 : 0);
+	int marker3_size = (name3 ? (int)strlen(name3) + 1 : 0);
 
 	if (marker_size <= 0)
 		marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
diff --git a/src/xdiff/xutils.c b/src/xdiff/xutils.c
index 9dea04bba..bb7bdee49 100644
--- a/src/xdiff/xutils.c
+++ b/src/xdiff/xutils.c
@@ -62,14 +62,14 @@ int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
 
 void *xdl_mmfile_first(mmfile_t *mmf, long *size)
 {
-	*size = mmf->size;
+	*size = (long)mmf->size;
 	return mmf->ptr;
 }
 
 
 long xdl_mmfile_size(mmfile_t *mmf)
 {
-	return mmf->size;
+	return (long)mmf->size;
 }
 
 
@@ -321,7 +321,7 @@ int xdl_num_out(char *out, long val) {
 		*str++ = '0';
 	*str = '\0';
 
-	return str - out;
+	return (int)(str - out);
 }
 
 
diff --git a/tests-clar/diff/diff_helpers.c b/tests-clar/diff/diff_helpers.c
index 055bd4bc3..c9a633cd0 100644
--- a/tests-clar/diff/diff_helpers.c
+++ b/tests-clar/diff/diff_helpers.c
@@ -5,7 +5,7 @@ git_tree *resolve_commit_oid_to_tree(
 	git_repository *repo,
 	const char *partial_oid)
 {
-	size_t len = strlen(partial_oid);
+	unsigned int len = (unsigned int)strlen(partial_oid);
 	git_oid oid;
 	git_object *obj = NULL;
 	git_tree *tree = NULL;
diff --git a/tests-clar/repo/open.c b/tests-clar/repo/open.c
index 2450de017..1813887ec 100644
--- a/tests-clar/repo/open.c
+++ b/tests-clar/repo/open.c
@@ -1,5 +1,6 @@
 #include "clar_libgit2.h"
 #include "fileops.h"
+#include <ctype.h>
 
 void test_repo_open__cleanup(void)
 {
@@ -234,7 +235,6 @@ void test_repo_open__win32_path(void)
 #ifdef GIT_WIN32
 	git_repository *repo = cl_git_sandbox_init("empty_standard_repo"), *repo2;
 	git_buf winpath = GIT_BUF_INIT;
-	char *src, *tgt;
 	static const char *repo_path = "empty_standard_repo/.git/";
 	static const char *repo_wd   = "empty_standard_repo/";
 
diff --git a/tests-clar/status/status_data.h b/tests-clar/status/status_data.h
index e60b67cb3..7f078bf60 100644
--- a/tests-clar/status/status_data.h
+++ b/tests-clar/status/status_data.h
@@ -1,11 +1,11 @@
 
 struct status_entry_counts {
-	int wrong_status_flags_count;
-	int wrong_sorted_path;
-	int entry_count;
+	size_t wrong_status_flags_count;
+	size_t wrong_sorted_path;
+	size_t entry_count;
 	const unsigned int* expected_statuses;
 	const char** expected_paths;
-	int expected_entry_count;
+	size_t expected_entry_count;
 };
 
 /* entries for a plain copy of tests/resources/status */
diff --git a/tests/t07-hashtable.c b/tests/t07-hashtable.c
index 6beaeac68..4d45c7fc1 100644
--- a/tests/t07-hashtable.c
+++ b/tests/t07-hashtable.c
@@ -112,7 +112,7 @@ BEGIN_TEST(table2, "make sure the table resizes automatically")
 
 	const int objects_n = 64;
 	int i;
-	unsigned int old_size;
+	size_t old_size;
 	table_item *objects;
 	git_hashtable *table = NULL;
 
diff --git a/tests/test_helpers.c b/tests/test_helpers.c
index fc0351977..a1689e34f 100644
--- a/tests/test_helpers.c
+++ b/tests/test_helpers.c
@@ -87,7 +87,7 @@ void locate_loose_object(const char *repository_folder, git_object *object, char
 	static const char *objects_folder = "objects/";
 
 	char *ptr, *full_path, *top_folder;
-	int path_length, objects_length;
+	size_t path_length, objects_length;
 
 	assert(repository_folder && object);