don't dereference NULL upon fdopen failure

There were several unchecked use of fdopen(); replace them with xfdopen()
that checks and dies.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-add.c

@@ -198,7 +198,7 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	out = open(file, O_CREAT | O_WRONLY, 0644);
 	if (out < 0)
 		die ("Could not open '%s' for writing.", file);
-	rev.diffopt.file = fdopen(out, "w");
+	rev.diffopt.file = xfdopen(out, "w");
 	rev.diffopt.close_file = 1;
 	if (run_diff_files(&rev, 0))
 		die ("Could not write patch");

builtin-mailsplit.c

@@ -64,7 +64,7 @@ static int split_one(FILE *mbox, const char *name, int allow_bare)
 	fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
 	if (fd < 0)
 		die_errno("cannot open output file '%s'", name);
-	output = fdopen(fd, "w");
+	output = xfdopen(fd, "w");
 
 	/* Copy it out, while searching for a line that begins with
 	 * "From " and having something that looks like a date format.

bundle.c

@@ -234,7 +234,7 @@ int create_bundle(struct bundle_header *header, const char *path,
 	rls.git_cmd = 1;
 	if (start_command(&rls))
 		return -1;
-	rls_fout = fdopen(rls.out, "r");
+	rls_fout = xfdopen(rls.out, "r");
 	while (fgets(buffer, sizeof(buffer), rls_fout)) {
 		unsigned char sha1[20];
 		if (buffer[0] == '-') {

transport-helper.c

@@ -39,7 +39,7 @@ static struct child_process *get_helper(struct transport *transport)
 
 	write_str_in_full(helper->in, "capabilities\n");
 
-	file = fdopen(helper->out, "r");
+	file = xfdopen(helper->out, "r");
 	while (1) {
 		if (strbuf_getline(&buf, file, '\n') == EOF)
 			exit(128); /* child died, message supplied already */
@@ -71,7 +71,7 @@ static int fetch_with_fetch(struct transport *transport,
 			    int nr_heads, const struct ref **to_fetch)
 {
 	struct child_process *helper = get_helper(transport);
-	FILE *file = fdopen(helper->out, "r");
+	FILE *file = xfdopen(helper->out, "r");
 	int i;
 	struct strbuf buf = STRBUF_INIT;
 
@@ -124,7 +124,7 @@ static struct ref *get_refs_list(struct transport *transport, int for_push)
 
 	write_str_in_full(helper->in, "list\n");
 
-	file = fdopen(helper->out, "r");
+	file = xfdopen(helper->out, "r");
 	while (1) {
 		char *eov, *eon;
 		if (strbuf_getline(&buf, file, '\n') == EOF)

upload-pack.c

@@ -108,7 +108,7 @@ static int do_rev_list(int fd, void *create_full_pack)
 	int i;
 	struct rev_info revs;
 
-	pack_pipe = fdopen(fd, "w");
+	pack_pipe = xfdopen(fd, "w");
 	init_revisions(&revs, NULL);
 	revs.tag_objects = 1;
 	revs.tree_objects = 1;
@@ -255,7 +255,7 @@ static void create_pack_file(void)
 
 	/* pass on revisions we (don't) want */
 	if (!shallow_nr) {
-		FILE *pipe_fd = fdopen(pack_objects.in, "w");
+		FILE *pipe_fd = xfdopen(pack_objects.in, "w");
 		if (!create_full_pack) {
 			int i;
 			for (i = 0; i < want_obj.nr; i++)