signature: straighten the creation of a signature

- Fails on empty name and/or email
 - Trims leading and trailing spaces of name and email

src/signature.c

@@ -33,26 +33,84 @@ void git_signature_free(git_signature *sig)
 	if (sig == NULL)
 		return;
 
-	free(sig->name);
-	free(sig->email);
+	if (sig->name)
+		free(sig->name);
+
+	if (sig->email)
+		free(sig->email);
+
 	free(sig);
 }
 
+static const char *skip_leading_spaces(const char *buffer, const char *buffer_end)
+{
+	while (*buffer == ' ' && buffer < buffer_end)
+		buffer++;
+
+	return buffer;
+}
+
+static const char *skip_trailing_spaces(const char *buffer_start, const char *buffer_end)
+{
+	while (*buffer_end == ' ' && buffer_end > buffer_start)
+		buffer_end--;
+
+	return buffer_end;
+}
+
+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;
+
+	left = skip_leading_spaces(input, input_end);
+	right = skip_trailing_spaces(input, input_end - 1);
+
+	if (right <= left)
+		if (fail_when_empty)
+			return git__throw(GIT_EINVALIDARGS, "Failed to trim. Input is either empty or only contains spaces");
+		else
+			right = left - 1;
+
+	trimmed_input_length = right - left + 1;
+
+	*storage = git__malloc(trimmed_input_length + 1);
+	if (*storage == NULL)
+		return GIT_ENOMEM;
+
+	memcpy(*storage, left, trimmed_input_length);
+	(*storage)[trimmed_input_length] = 0;
+
+	return GIT_SUCCESS;
+}
+
 git_signature *git_signature_new(const char *name, const char *email, git_time_t time, int offset)
 {
+	int error;
 	git_signature *p = NULL;
 
+	assert(name && email);
+
 	if ((p = git__malloc(sizeof(git_signature))) == NULL)
 		goto cleanup;
 
-	p->name = git__strdup(name);
-	p->email = git__strdup(email);
+	memset(p, 0x0, sizeof(git_signature));
+
+	error = process_trimming(name, &p->name, name + strlen(name), 1);
+	if (error < GIT_SUCCESS) {
+		git__rethrow(GIT_EINVALIDARGS, "Failed to create signature. 'name' argument is invalid");
+		goto cleanup;
+	}
+
+	error = process_trimming(email, &p->email, email + strlen(email), 1);
+	if (error < GIT_SUCCESS) {
+		git__rethrow(GIT_EINVALIDARGS, "Failed to create signature. 'email' argument is invalid");
+		goto cleanup;
+	}
+
 	p->when.time = time;
 	p->when.offset = offset;
 
-	if (p->name == NULL || p->email == NULL)
-		goto cleanup;
-
 	return p;
 
 cleanup:
@@ -149,46 +207,28 @@ static int parse_timezone_offset(const char *buffer, int *offset_out)
 }
 
 int process_next_token(const char **buffer_out, char **storage,
-	const char *token_end, const char *line_end)
+	const char *token_end, const char *right_boundary)
 {
-	int name_length = 0;
-	const char *buffer = *buffer_out;
+	int error = process_trimming(*buffer_out, storage, token_end, 0);
+	if (error < GIT_SUCCESS)
+		return error;
 
-	/* Skip leading spaces before the name */
-	while (*buffer == ' ' && buffer < line_end)
-		buffer++;
+	*buffer_out = token_end + 1;
 
-	name_length = token_end - buffer;
-
-	/* Trim trailing spaces after the name */
-	while (buffer[name_length - 1] == ' ' && name_length > 0)
-		name_length--;
-
-	*storage = git__malloc(name_length + 1);
-	if (*storage == NULL)
-		return GIT_ENOMEM;
-
-	memcpy(*storage, buffer, name_length);
-	(*storage)[name_length] = 0;
-	buffer = token_end + 1;
-
-	if (buffer > line_end)
+	if (*buffer_out > right_boundary)
 		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse signature. Signature too short");
 
-	*buffer_out = buffer;
 	return GIT_SUCCESS;
 }
 
-const char* scan_for_previous_token(const char *buffer, const char *left_boundary)
+const char *scan_for_previous_token(const char *buffer, const char *left_boundary)
 {
-	const char *start = buffer;
+	const char *start;
 
-	if (start <= left_boundary)
+	if (buffer <= left_boundary)
 		return NULL;
 
-	/* Trim potential trailing spaces */
-	while (*start == ' ' && start > left_boundary)
-		start--;
+	start = skip_trailing_spaces(left_boundary, buffer);
 
 	/* Search for previous occurence of space */
 	while (start[-1] != ' ' && start > left_boundary)

tests/t04-commit.c

@@ -331,7 +331,6 @@ BEGIN_TEST(parse1, "parse the signature line in a commit")
 		123456,
 		-60);
 
-
 	/* Parse an obviously invalid signature */
 	TEST_SIGNATURE_PASS(
 		"committer <>\n",
@@ -446,6 +445,39 @@ BEGIN_TEST(parse1, "parse the signature line in a commit")
 
 END_TEST
 
+static int try_build_signature(const char *name, const char *email, git_time_t time, int offset)
+{
+	git_signature *sign;
+	int error = GIT_SUCCESS;
+
+	sign = git_signature_new(name, email, time, offset);
+
+	if (sign == NULL)
+		error = GIT_ERROR;
+
+	git_signature_free((git_signature *)sign);
+
+	return error;
+}
+
+BEGIN_TEST(signature0, "creating a signature trims leading and trailing spaces")
+	git_signature *sign;
+	sign = git_signature_new("  nulltoken ", "   emeric.fermas@gmail.com     ", 1234567890, 60);
+	must_be_true(sign != NULL);
+	must_pass(strcmp(sign->name, "nulltoken"));
+	must_pass(strcmp(sign->email, "emeric.fermas@gmail.com"));
+	git_signature_free((git_signature *)sign);
+END_TEST
+
+BEGIN_TEST(signature1, "can not create a signature with empty name or email")
+	must_pass(try_build_signature("nulltoken", "emeric.fermas@gmail.com", 1234567890, 60));
+
+	must_fail(try_build_signature("", "emeric.fermas@gmail.com", 1234567890, 60));
+	must_fail(try_build_signature("   ", "emeric.fermas@gmail.com", 1234567890, 60));
+	must_fail(try_build_signature("nulltoken", "", 1234567890, 60));
+	must_fail(try_build_signature("nulltoken", "  ", 1234567890, 60));
+END_TEST
+
 /* External declaration for testing the buffer parsing method */
 int commit_parse_buffer(git_commit *commit, void *data, size_t len, unsigned int parse_flags);
 
@@ -722,4 +754,7 @@ BEGIN_SUITE(commit)
 	ADD_TEST(write0);
 
 	ADD_TEST(root0);
+
+	ADD_TEST(signature0);
+	ADD_TEST(signature1);
 END_SUITE