Merge pull request libgit2#6625 from libgit2/ethomson/error_updates

include/git2/errors.h

@@ -118,63 +118,22 @@ typedef enum {
  * Return the last `git_error` object that was generated for the
  * current thread.
  *
- * The default behaviour of this function is to return NULL if no previous error has occurred.
- * However, libgit2's error strings are not cleared aggressively, so a prior
- * (unrelated) error may be returned. This can be avoided by only calling
- * this function if the prior call to a libgit2 API returned an error.
+ * This function will never return NULL.
  *
- * @return A git_error object.
- */
-GIT_EXTERN(const git_error *) git_error_last(void);
-
-/**
- * Clear the last library error that occurred for this thread.
- */
-GIT_EXTERN(void) git_error_clear(void);
-
-/**
- * Set the error message string for this thread, using `printf`-style
- * formatting.
- *
- * This function is public so that custom ODB backends and the like can
- * relay an error message through libgit2.  Most regular users of libgit2
- * will never need to call this function -- actually, calling it in most
- * circumstances (for example, calling from within a callback function)
- * will just end up having the value overwritten by libgit2 internals.
+ * Callers should not rely on this to determine whether an error has
+ * occurred. For error checking, callers should examine the return
+ * codes of libgit2 functions.
  *
- * This error message is stored in thread-local storage and only applies
- * to the particular thread that this libgit2 call is made from.
+ * This call can only reliably report error messages when an error
+ * has occurred. (It may contain stale information if it is called
+ * after a different function that succeeds.)
  *
- * @param error_class One of the `git_error_t` enum above describing the
- *                    general subsystem that is responsible for the error.
- * @param fmt The `printf`-style format string; subsequent arguments must
- *            be the arguments for the format string.
- */
-GIT_EXTERN(void) git_error_set(int error_class, const char *fmt, ...)
-                 GIT_FORMAT_PRINTF(2, 3);
-
-/**
- * Set the error message string for this thread.  This function is like
- * `git_error_set` but takes a static string instead of a `printf`-style
- * format.
+ * The memory for this object is managed by libgit2. It should not
+ * be freed.
  *
- * @param error_class One of the `git_error_t` enum above describing the
- *                    general subsystem that is responsible for the error.
- * @param string The error message to keep
- * @return 0 on success or -1 on failure
- */
-GIT_EXTERN(int) git_error_set_str(int error_class, const char *string);
-
-/**
- * Set the error message to a special value for memory allocation failure.
- *
- * The normal `git_error_set_str()` function attempts to `strdup()` the
- * string that is passed in.  This is not a good idea when the error in
- * question is a memory allocation failure.  That circumstance has a
- * special setter function that sets the error string to a known and
- * statically allocated internal value.
+ * @return A git_error object.
  */
-GIT_EXTERN(void) git_error_set_oom(void);
+GIT_EXTERN(const git_error *) git_error_last(void);
 
 /** @} */
 GIT_END_DECL

include/git2/sys/errors.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#ifndef INCLUDE_sys_git_errors_h__
+#define INCLUDE_sys_git_errors_h__
+
+#include "git2/common.h"
+
+GIT_BEGIN_DECL
+
+/**
+ * Clear the last library error that occurred for this thread.
+ */
+GIT_EXTERN(void) git_error_clear(void);
+
+/**
+ * Set the error message string for this thread, using `printf`-style
+ * formatting.
+ *
+ * This function is public so that custom ODB backends and the like can
+ * relay an error message through libgit2.  Most regular users of libgit2
+ * will never need to call this function -- actually, calling it in most
+ * circumstances (for example, calling from within a callback function)
+ * will just end up having the value overwritten by libgit2 internals.
+ *
+ * This error message is stored in thread-local storage and only applies
+ * to the particular thread that this libgit2 call is made from.
+ *
+ * @param error_class One of the `git_error_t` enum above describing the
+ *                    general subsystem that is responsible for the error.
+ * @param fmt The `printf`-style format string; subsequent arguments must
+ *            be the arguments for the format string.
+ */
+GIT_EXTERN(void) git_error_set(int error_class, const char *fmt, ...)
+                 GIT_FORMAT_PRINTF(2, 3);
+
+/**
+ * Set the error message string for this thread.  This function is like
+ * `git_error_set` but takes a static string instead of a `printf`-style
+ * format.
+ *
+ * @param error_class One of the `git_error_t` enum above describing the
+ *                    general subsystem that is responsible for the error.
+ * @param string The error message to keep
+ * @return 0 on success or -1 on failure
+ */
+GIT_EXTERN(int) git_error_set_str(int error_class, const char *string);
+
+/**
+ * Set the error message to a special value for memory allocation failure.
+ *
+ * The normal `git_error_set_str()` function attempts to `strdup()` the
+ * string that is passed in.  This is not a good idea when the error in
+ * question is a memory allocation failure.  That circumstance has a
+ * special setter function that sets the error string to a known and
+ * statically allocated internal value.
+ */
+GIT_EXTERN(void) git_error_set_oom(void);
+
+GIT_END_DECL
+
+#endif

src/libgit2/clone.c

@@ -542,15 +542,15 @@ static int git__clone(
 	}
 
 	if (error != 0) {
-		git_error_state last_error = {0};
-		git_error_state_capture(&last_error, error);
+		git_error *last_error;
+		git_error_save(&last_error);
 
 		git_repository_free(repo);
 		repo = NULL;
 
 		(void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);
 
-		git_error_state_restore(&last_error);
+		git_error_restore(last_error);
 	}
 
 	*out = repo;