Teach 'git-send-pack' to send new branches and tags.

The protocol always supported it, but send-pack didn't actually know how
to tell the other side about a new branch/tag.

NOTE! You'll have to name it explicitly on the command line: if you
don't name any branches, git-send-pack will default to the branches that
already exist.

diff --git a/send-pack.c b/send-pack.c
index 7287c3d..4c6adab 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "refs.h"
 #include "pkt-line.h"
 
 static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
@@ -11,6 +12,17 @@ struct ref {
        char name[0];
 };
 
+static int is_zero_sha1(const unsigned char *sha1)
+{
+       int i;
+
+       for (i = 0; i < 20; i++) {
+               if (*sha1++)
+                       return 0;
+       }
+       return 1;
+}
+
 static void exec_pack_objects(void)
 {
        static char *args[] = {
@@ -33,11 +45,15 @@ static void exec_rev_list(struct ref *refs)
                char *buf = malloc(100);
                if (i > 900)
                        die("git-rev-list environment overflow");
-               args[i++] = buf;
-               snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
-               buf += 50;
-               args[i++] = buf;
-               snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
+               if (!is_zero_sha1(refs->old_sha1)) {
+                       args[i++] = buf;
+                       snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
+                       buf += 50;
+               }
+               if (!is_zero_sha1(refs->new_sha1)) {
+                       args[i++] = buf;
+                       snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
+               }
                refs = refs->next;
        }
        args[i] = NULL;
@@ -104,14 +120,54 @@ static int read_ref(const char *ref, unsigned char *sha1)
        return ret;
 }
 
+static int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
+{
+       if (!has_sha1_file(old_sha1))
+               return 0;
+       /*
+        * FIXME! It is not correct to say that the new one is newer
+        * just because we don't have the old one!
+        *
+        * We should really see if we can reach the old_sha1 commit
+        * from the new_sha1 one.
+        */
+       return 1;
+}
+
+static int local_ref_nr_match;
+static char **local_ref_match;
+static struct ref **local_ref_list;
+
+static int try_to_match(const char *refname, const unsigned char *sha1)
+{
+       struct ref *ref;
+       int len;
+
+       if (!path_match(refname, local_ref_nr_match, local_ref_match))
+               return 0;
+
+       len = strlen(refname)+1;
+       ref = xmalloc(sizeof(*ref) + len);
+       memset(ref->old_sha1, 0, 20);
+       memcpy(ref->new_sha1, sha1, 20);
+       memcpy(ref->name, refname, len);
+       ref->next = NULL;
+       *local_ref_list = ref;
+       local_ref_list = &ref->next;
+       return 0;
+}
+
 static int send_pack(int in, int out, int nr_match, char **match)
 {
        struct ref *ref_list = NULL, **last_ref = &ref_list;
        struct ref *ref;
+       int new_refs;
 
+       /*
+        * Read all the refs from the other end
+        */
        for (;;) {
                unsigned char old_sha1[20];
-               unsigned char new_sha1[20];
                static char buffer[1000];
                char *name;
                int len;
@@ -125,27 +181,65 @@ static int send_pack(int in, int out, int nr_match, char **match)
                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
                        die("protocol error: expected sha/ref, got '%s'", buffer);
                name = buffer + 41;
+               ref = xmalloc(sizeof(*ref) + len - 40);
+               memcpy(ref->old_sha1, old_sha1, 20);
+               memset(ref->new_sha1, 0, 20);
+               memcpy(ref->name, buffer + 41, len - 40);
+               ref->next = NULL;
+               *last_ref = ref;
+               last_ref = &ref->next;
+       }
+
+       /*
+        * Go through the refs, see if we want to update
+        * any of them..
+        */
+       for (ref = ref_list; ref; ref = ref->next) {
+               unsigned char new_sha1[20];
+               char *name = ref->name;
+
                if (nr_match && !path_match(name, nr_match, match))
                        continue;
+
                if (read_ref(name, new_sha1) < 0)
-                       return error("no such local reference '%s'", name);
-               if (!has_sha1_file(old_sha1))
-                       return error("remote '%s' points to object I don't have", name);
-               if (!memcmp(old_sha1, new_sha1, 20)) {
+                       continue;
+
+               if (nr_match && !path_match(name, nr_match, match))
+                       continue;
+
+               if (!memcmp(ref->old_sha1, new_sha1, 20)) {
                        fprintf(stderr, "'%s' unchanged\n", name);
                        continue;
                }
-               ref = xmalloc(sizeof(*ref) + len - 40);
-               memcpy(ref->old_sha1, old_sha1, 20);
+
+               if (!ref_newer(new_sha1, ref->old_sha1)) {
+                       error("remote '%s' points to object I don't have", name);
+                       continue;
+               }
+
+               /* Ok, mark it for update */
                memcpy(ref->new_sha1, new_sha1, 20);
-               memcpy(ref->name, buffer + 41, len - 40);
-               ref->next = NULL;
-               *last_ref = ref;
-               last_ref = &ref->next;
        }
 
+       /*
+        * See if we have any refs that the other end didn't have
+        */
+       if (nr_match) {
+               local_ref_nr_match = nr_match;
+               local_ref_match = match;
+               local_ref_list = last_ref;
+               for_each_ref(try_to_match);
+       }
+
+       /*
+        * Finally, tell the other end!
+        */
+       new_refs = 0;
        for (ref = ref_list; ref; ref = ref->next) {
                char old_hex[60], *new_hex;
+               if (is_zero_sha1(ref->new_sha1))
+                       continue;
+               new_refs++;
                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
                new_hex = sha1_to_hex(ref->new_sha1);
                packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
@@ -153,7 +247,7 @@ static int send_pack(int in, int out, int nr_match, char **match)
        }
        
        packet_flush(out);
-       if (ref_list)
+       if (new_refs)
                pack_objects(out, ref_list);
        close(out);
        return 0;