[PATCH] Fix export_marks() error handling.

[Matthias Andree <matthias.andree@gmx.de>]

- Don't leak one FILE * on error per export_marks() call. Found with
  cppcheck and reported by Martin Ettl.

- Abort the potentially long for(;idnums.size;) loop on write errors.

- Add a trailing full-stop to error message when fopen() fails.

Signed-off-by: Matthias Andree <matthias.andree@gmx.de>
---
 builtin-fast-export.c |   15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/builtin-fast-export.c b/builtin-fast-export.c
index 9a8a6fc..6c0956d 100644
--- a/builtin-fast-export.c
+++ b/builtin-fast-export.c
@@ -428,21 +428,30 @@ static void export_marks(char *file)
 	uint32_t mark;
 	struct object_decoration *deco = idnums.hash;
 	FILE *f;
+	int e;
 
 	f = fopen(file, "w");
 	if (!f)
-		error("Unable to open marks file %s for writing", file);
+		error("Unable to open marks file %s for writing.", file);
 
 	for (i = 0; i < idnums.size; i++) {
 		if (deco->base && deco->base->type == 1) {
 			mark = ptr_to_mark(deco->decoration);
-			fprintf(f, ":%"PRIu32" %s\n", mark,
+			e = fprintf(f, ":%"PRIu32" %s\n", mark,
 				sha1_to_hex(deco->base->sha1));
+			if (e < 0) break;
 		}
 		deco++;
 	}
 
-	if (ferror(f) || fclose(f))
+	/* do not optimize the next two lines - they must both be executed in
+	 * this order. || might short-circuit the fclose(), and combining them
+	 * into one statement might reverse the order of execution.
+	 * Also, fflush() may not be sufficient - on some file systems, the
+	 * error is still delayed until the final [f]close().  */
+	e  = ferror(f);
+	e |= fclose(f);
+	if (e)
 		error("Unable to write marks file %s.", file);
 }
 
-- 
1.6.3.3.385.g60647