error-handling: On-disk config file backend

Includes:

	- Proper error reporting when encountering syntax errors in a
	config file (file, line number, column).

	- Rewritten `config_write`, now with 99% less goto-spaghetti

	- Error state in `git_filebuf`: filebuf write functions no longer
	need to be checked for error returns. If any of the writes performed
	on a buffer fail, the last call to `git_filebuf_commit` or
	`git_filebuf_hash` will fail accordingly and set the appropiate error
	message. Baller!

1 files changed, 12 insertions, 0 deletions

diff --git a/src/common.h b/src/common.h
index 0b4dc2e49..30757de70 100644
--- a/src/common.h
+++ b/src/common.h
@@ -46,6 +46,8 @@
 #include "thread-utils.h"
 #include "bswap.h"
 
+#include <regex.h>
+
 extern void git___throw(const char *, ...) GIT_FORMAT_PRINTF(1, 2);
 #define git__throw(error, ...) \
 	(git___throw(__VA_ARGS__), error)
@@ -54,6 +56,16 @@ extern void git___rethrow(const char *, ...) GIT_FORMAT_PRINTF(1, 2);
 #define git__rethrow(error, ...) \
 	(git___rethrow(__VA_ARGS__), error)
 
+
+#define GITERR_CHECK_ALLOC(ptr) if (ptr == NULL) { return -1; }
+
+void giterr_set_oom(void);
+void giterr_set(int error_class, const char *string, ...);
+void giterr_clear(void);
+void giterr_set_str(int error_class, const char *string);
+void giterr_set_regex(const regex_t *regex, int error_code);
+
+
 #include "util.h"