Improve GIT_EUSER handling

This adds giterr_user_cancel to return GIT_EUSER and clear any
error message that is sitting around.  As a result of using that
in places, we need to be more thorough with capturing errors that
happen inside a callback when used internally.  To help with that,
this also adds giterr_capture and giterr_restore so that when we
internally use a foreach-type function that clears errors and
converts them to GIT_EUSER, it is easier to restore not just the
return value, but the actual error message text.

1 files changed, 3 insertions, 9 deletions

diff --git a/src/iterator.c b/src/iterator.c
index 8646399ab..c1292227c 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -991,9 +991,8 @@ static int fs_iterator__expand_dir(fs_iterator *fi)
 		fi->base.start, fi->base.end, &ff->entries);
 
 	if (error < 0) {
-		git_error last_error = {0};
-
-		giterr_detach(&last_error);
+		git_error_state last_error = { 0 };
+		giterr_capture(&last_error, error);
 
 		/* these callbacks may clear the error message */
 		fs_iterator__free_frame(ff);
@@ -1001,12 +1000,7 @@ static int fs_iterator__expand_dir(fs_iterator *fi)
 		/* next time return value we skipped to */
 		fi->base.flags &= ~GIT_ITERATOR_FIRST_ACCESS;
 
-		if (last_error.message) {
-			giterr_set_str(last_error.klass, last_error.message);
-			free(last_error.message);
-		}
-
-		return error;
+		return giterr_restore(&last_error);
 	}
 
 	if (ff->entries.length == 0) {