diff --git a/src/checkout.c b/src/checkout.c
index 0ce283beb..59cd218a9 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -64,6 +64,7 @@ static int checkout_notify(
 {
 	git_diff_file wdfile;
 	const git_diff_file *baseline = NULL, *target = NULL, *workdir = NULL;
+	const char *path = NULL;
 
 	if (!data->opts.notify_cb)
 		return 0;
@@ -81,6 +82,8 @@ static int checkout_notify(
 		wdfile.mode = wditem->mode;
 
 		workdir = &wdfile;
+
+		path = wditem->path;
 	}
 
 	if (delta) {
@@ -101,11 +104,12 @@ static int checkout_notify(
 			baseline = &delta->old_file;
 			break;
 		}
+
+		path = delta->old_file.path;
 	}
 
 	return data->opts.notify_cb(
-		why, delta ? delta->old_file.path : wditem->path,
-		baseline, target, workdir, data->opts.notify_payload);
+		why, path, baseline, target, workdir, data->opts.notify_payload);
 }
 
 static bool checkout_is_workdir_modified(
@@ -683,7 +687,7 @@ static int blob_content_to_file(
 {
 	int error = -1, nb_filters = 0;
 	mode_t file_mode = opts->file_mode;
-	bool dont_free_filtered = false;
+	bool dont_free_filtered;
 	git_buf unfiltered = GIT_BUF_INIT, filtered = GIT_BUF_INIT;
 	git_vector filters = GIT_VECTOR_INIT;
 
diff --git a/src/diff_output.c b/src/diff_output.c
index 26b073aad..88ccc9d45 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -1280,14 +1280,15 @@ static void set_data_from_buffer(
 {
 	file->size = (git_off_t)buffer_len;
 	file->mode = 0644;
-
-	if (!buffer)
-		file->flags |= GIT_DIFF_FILE_NO_DATA;
-	else
-		git_odb_hash(&file->oid, buffer, buffer_len, GIT_OBJ_BLOB);
-
 	map->len   = buffer_len;
-	map->data  = (char *)buffer;
+
+	if (!buffer) {
+		file->flags |= GIT_DIFF_FILE_NO_DATA;
+		map->data = NULL;
+	} else {
+		map->data = (char *)buffer;
+		git_odb_hash(&file->oid, buffer, buffer_len, GIT_OBJ_BLOB);
+	}
 }
 
 typedef struct {
diff --git a/src/notes.c b/src/notes.c
index eff80bc82..f5537db3f 100644
--- a/src/notes.c
+++ b/src/notes.c
@@ -147,7 +147,7 @@ static int manipulate_note_in_tree_r(
 		int fanout,
 		int current_error))
 {
-	int error = -1;
+	int error;
 	git_tree *subtree = NULL, *new = NULL;
 	char subtree_name[3];
 
diff --git a/src/refs.c b/src/refs.c
index 7dabfefae..866c230e6 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -1493,7 +1493,7 @@ int git_reference_foreach(
 	/* list all the packed references first */
 	if (list_flags & GIT_REF_PACKED) {
 		const char *ref_name;
-		void *ref;
+		void *ref = NULL;
 		GIT_UNUSED(ref);
 
 		if (packed_load(repo) < 0)
diff --git a/src/transports/winhttp.c b/src/transports/winhttp.c
index 64bfece34..970fa53bd 100644
--- a/src/transports/winhttp.c
+++ b/src/transports/winhttp.c
@@ -88,7 +88,7 @@ static int apply_basic_credential(HINTERNET request, git_cred *cred)
 	git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
 	git_buf buf = GIT_BUF_INIT, raw = GIT_BUF_INIT;
 	wchar_t *wide = NULL;
-	int error = -1, wide_len;
+	int error = -1, wide_len = 0;
 
 	git_buf_printf(&raw, "%s:%s", c->username, c->password);
 
diff --git a/tests-clar/clar_libgit2.c b/tests-clar/clar_libgit2.c
index 63efd5954..698aa90f0 100644
--- a/tests-clar/clar_libgit2.c
+++ b/tests-clar/clar_libgit2.c
@@ -86,14 +86,18 @@ int cl_setenv(const char *name, const char *value)
 
 	git__utf8_to_16(name_utf16, GIT_WIN_PATH, name);
 
-	if (value != NULL)
+	if (value) {
 		git__utf8_to_16(value_utf16, GIT_WIN_PATH, value);
+		cl_assert(SetEnvironmentVariableW(name_utf16, value_utf16));
+	} else {
+		/* Windows XP returns 0 (failed) when passing NULL for lpValue when
+		 * lpName does not exist in the environment block. This behavior
+		 * seems to have changed in later versions. Don't check return value
+		 * of SetEnvironmentVariable when passing NULL for lpValue.
+		 */
+		SetEnvironmentVariableW(name_utf16, NULL);
+	}
 
-	/* Windows XP returns 0 (failed) when passing NULL for lpValue when lpName
-	 * does not exist in the environment block. This behavior seems to have changed
-	 * in later versions. Don't fail when SetEnvironmentVariable fails, if we passed
-	 * NULL for lpValue. */
-	cl_assert(SetEnvironmentVariableW(name_utf16, value ? value_utf16 : NULL) || !value);
 	return 0;
 }
 
diff --git a/tests-clar/core/env.c b/tests-clar/core/env.c
index fa48de17e..2f5e91f71 100644
--- a/tests-clar/core/env.c
+++ b/tests-clar/core/env.c
@@ -74,6 +74,8 @@ void test_core_env__0(void)
 	char **val;
 
 	memset(testfile, 0, sizeof(testfile));
+	cl_assert_equal_s("", testfile);
+
 	memcpy(testfile, "testfile", 8);
 	cl_assert_equal_s("testfile", testfile);