test: Properly show error messages

include/git2/errors.h

@@ -146,6 +146,11 @@ GIT_EXTERN(const char *) git_lasterror(void);
  */
 GIT_EXTERN(const char *) git_strerror(int num);
 
+/**
+ * Clear the latest library error
+ */
+GIT_EXTERN(void) git_clearerror(void);
+
 /** @} */
 GIT_END_DECL
 #endif

src/errors.c

@@ -108,6 +108,13 @@ int git__throw(int error, const char *msg, ...)
 
 const char *git_lasterror(void)
 {
+	if (!g_last_error[0])
+		return NULL;
+
 	return g_last_error;
 }
 
+void git_clearerror(void)
+{
+	g_last_error[0] = '\0';
+}

src/fileops.c

@@ -123,8 +123,7 @@ int gitfo_isdir(const char *path)
 	struct stat st;
 	int len, stat_error;
 
-	if (!path)
-		return git__throw(GIT_ENOTFOUND, "No path given to gitfo_isdir");
+	assert(path);
 
 	len = strlen(path);
 
@@ -140,10 +139,10 @@ int gitfo_isdir(const char *path)
 	}
 
 	if (stat_error < GIT_SUCCESS)
-		return git__throw(GIT_ENOTFOUND, "%s does not exist", path);
+		return GIT_ERROR;
 
 	if (!S_ISDIR(st.st_mode))
-		return git__throw(GIT_ENOTFOUND, "%s is not a directory", path);
+		return GIT_ERROR;
 
 	return GIT_SUCCESS;
 }

tests/test_lib.c

@@ -77,13 +77,16 @@ void git_test__init(git_test *t, const char *name, const char *description)
 static void fail_test(git_test *tc, const char *file, int line, const char *message)
 {
 	char buf[1024];
+	const char *last_error = git_lasterror();
 
 	snprintf(buf, 1024, "%s:%d", file, line);
 
 	tc->failed = 1;
 	tc->message = strdup(message);
 	tc->failed_pos = strdup(buf);
-	tc->error_message = strdup(git_lasterror());
+
+	if (last_error)
+		tc->error_message = strdup(last_error);
 
 	if (tc->jump != 0)
 		longjmp(*(tc->jump), 0);

tests/test_lib.h

@@ -26,6 +26,7 @@
 #define BEGIN_TEST(TNAME, DESC) \
 	static void _gittest__##TNAME(git_test *_gittest) { \
 		git_test__init(_gittest, #TNAME, DESC); \
+		git_clearerror();\
 		{\
 
 #define END_TEST }}