[PATCH v6 16/44] builtin/apply: make gitdiff_*() return -1 on error

[Christian Couder <christian.couder@gmail.com>]

To libify `git apply` functionality we have to signal errors to the
caller instead of die()ing.

To do that in a compatible manner with the rest of the error handling
in "builtin/apply.c", gitdiff_*() functions should return -1 instead
of calling die().

A previous patch made it possible for gitdiff_*() functions to
return -1 in case of error. Let's take advantage of that to
make gitdiff_verify_name() return -1 on error, and to have
gitdiff_oldname() and gitdiff_newname() directly return
what gitdiff_verify_name() returns.

Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 builtin/apply.c | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/builtin/apply.c b/builtin/apply.c
index 1142514..b506369 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -827,54 +827,56 @@ static int gitdiff_hdrend(struct apply_state *state,
 #define DIFF_OLD_NAME 0
 #define DIFF_NEW_NAME 1
 
-static void gitdiff_verify_name(struct apply_state *state,
-				const char *line,
-				int isnull,
-				char **name,
-				int side)
+static int gitdiff_verify_name(struct apply_state *state,
+			       const char *line,
+			       int isnull,
+			       char **name,
+			       int side)
 {
 	if (!*name && !isnull) {
 		*name = find_name(state, line, NULL, state->p_value, TERM_TAB);
-		return;
+		return 0;
 	}
 
 	if (*name) {
 		int len = strlen(*name);
 		char *another;
 		if (isnull)
-			die(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
-			    *name, state->linenr);
+			return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
+				     *name, state->linenr);
 		another = find_name(state, line, NULL, state->p_value, TERM_TAB);
-		if (!another || memcmp(another, *name, len + 1))
-			die((side == DIFF_NEW_NAME) ?
+		if (!another || memcmp(another, *name, len + 1)) {
+			free(another);
+			return error((side == DIFF_NEW_NAME) ?
 			    _("git apply: bad git-diff - inconsistent new filename on line %d") :
 			    _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
+		}
 		free(another);
 	} else {
 		/* expect "/dev/null" */
 		if (memcmp("/dev/null", line, 9) || line[9] != '\n')
-			die(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
+			return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
 	}
+
+	return 0;
 }
 
 static int gitdiff_oldname(struct apply_state *state,
 			   const char *line,
 			   struct patch *patch)
 {
-	gitdiff_verify_name(state, line,
-			    patch->is_new, &patch->old_name,
-			    DIFF_OLD_NAME);
-	return 0;
+	return gitdiff_verify_name(state, line,
+				   patch->is_new, &patch->old_name,
+				   DIFF_OLD_NAME);
 }
 
 static int gitdiff_newname(struct apply_state *state,
 			   const char *line,
 			   struct patch *patch)
 {
-	gitdiff_verify_name(state, line,
-			    patch->is_delete, &patch->new_name,
-			    DIFF_NEW_NAME);
-	return 0;
+	return gitdiff_verify_name(state, line,
+				   patch->is_delete, &patch->new_name,
+				   DIFF_NEW_NAME);
 }
 
 static int gitdiff_oldmode(struct apply_state *state,
-- 
2.9.0.rc2.362.g3cd93d0