Merge branch 'jk/push-deadlock-regression-fix' into maint

"git push" had a handful of codepaths that could lead to a deadlock
when unexpected error happened, which has been fixed.

* jk/push-deadlock-regression-fix:
send-pack: report signal death of pack-objects
send-pack: read "unpack" status even on pack-objects failure
send-pack: improve unpack-status error messages
send-pack: use skip_prefix for parsing unpack status
send-pack: extract parsing of "unpack" response
receive-pack: fix deadlock when we cannot create tmpdir

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 1dbb8a069225be1e9d9fe27ad4b83a8bd66ca511..8672825e2e57fc0d17dcc65bbf482fb1d476684f 100644 (file)
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1664,8 +1664,11 @@ static const char *unpack(int err_fd, struct shallow_info *si)
        }
 
        tmp_objdir = tmp_objdir_create();
-       if (!tmp_objdir)
+       if (!tmp_objdir) {
+               if (err_fd > 0)
+                       close(err_fd);
                return "unable to create temporary object directory";
+       }
        child.env = tmp_objdir_env(tmp_objdir);
 
        /*

diff --git a/send-pack.c b/send-pack.c
index 6195b43e9abacf346f52b6bbb758c9ca7b617d4e..d2d2a49a0231293e98ab8546945f8d3ef9fa205d 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -72,6 +72,7 @@ static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, stru
        struct child_process po = CHILD_PROCESS_INIT;
        FILE *po_in;
        int i;
+       int rc;
 
        i = 4;
        if (args->use_thin_pack)
@@ -125,27 +126,44 @@ static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, stru
                po.out = -1;
        }
 
-       if (finish_command(&po))
+       rc = finish_command(&po);
+       if (rc) {
+               /*
+                * For a normal non-zero exit, we assume pack-objects wrote
+                * something useful to stderr. For death by signal, though,
+                * we should mention it to the user. The exception is SIGPIPE
+                * (141), because that's a normal occurence if the remote end
+                * hangs up (and we'll report that by trying to read the unpack
+                * status).
+                */
+               if (rc > 128 && rc != 141)
+                       error("pack-objects died of signal %d", rc - 128);
                return -1;
+       }
+       return 0;
+}
+
+static int receive_unpack_status(int in)
+{
+       const char *line = packet_read_line(in, NULL);
+       if (!skip_prefix(line, "unpack ", &line))
+               return error(_("unable to parse remote unpack status: %s"), line);
+       if (strcmp(line, "ok"))
+               return error(_("remote unpack failed: %s"), line);
        return 0;
 }
 
 static int receive_status(int in, struct ref *refs)
 {
        struct ref *hint;
-       int ret = 0;
-       char *line = packet_read_line(in, NULL);
-       if (!starts_with(line, "unpack "))
-               return error("did not receive remote status");
-       if (strcmp(line, "unpack ok")) {
-               error("unpack failed: %s", line + 7);
-               ret = -1;
-       }
+       int ret;
+
        hint = NULL;
+       ret = receive_unpack_status(in);
        while (1) {
                char *refname;
                char *msg;
-               line = packet_read_line(in, NULL);
+               char *line = packet_read_line(in, NULL);
                if (!line)
                        break;
                if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
@@ -557,6 +575,14 @@ int send_pack(struct send_pack_args *args,
                                close(out);
                        if (git_connection_is_socket(conn))
                                shutdown(fd[0], SHUT_WR);
+
+                       /*
+                        * Do not even bother with the return value; we know we
+                        * are failing, and just want the error() side effects.
+                        */
+                       if (status_report)
+                               receive_unpack_status(in);
+
                        if (use_sideband) {
                                close(demux.out);
                                finish_async(&demux);