Get rid of the dependency on RCS' merge program

diff --git a/connect.c b/connect.c
index 06ef387649e0645b934f3294df8b843aa328393f..f7edba82c4d2fcc642ccae785aa7a315b1f819d6 100644 (file)
--- a/connect.c
+++ b/connect.c
@@ -17,7 +17,7 @@ static int check_ref(const char *name, int len, unsigned int flags)
        if (!flags)
                return 1;
 
-       if (len > 45 || memcmp(name, "refs/", 5))
+       if (len < 5 || memcmp(name, "refs/", 5))
                return 0;
 
        /* Skip the "refs/" part */
@@ -144,6 +144,7 @@ struct refspec {
  * +A:B means overwrite remote B with local A.
  * +A is a shorthand for +A:A.
  * A is a shorthand for A:A.
+ * :B means delete remote B.
  */
 static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 {
@@ -174,21 +175,58 @@ static int count_refspec_match(const char *pattern,
                               struct ref *refs,
                               struct ref **matched_ref)
 {
-       int match;
        int patlen = strlen(pattern);
+       struct ref *matched_weak = NULL;
+       struct ref *matched = NULL;
+       int weak_match = 0;
+       int match = 0;
 
-       for (match = 0; refs; refs = refs->next) {
+       for (weak_match = match = 0; refs; refs = refs->next) {
                char *name = refs->name;
                int namelen = strlen(name);
+               int weak_match;
+
                if (namelen < patlen ||
                    memcmp(name + namelen - patlen, pattern, patlen))
                        continue;
                if (namelen != patlen && name[namelen - patlen - 1] != '/')
                        continue;
-               match++;
-               *matched_ref = refs;
+
+               /* A match is "weak" if it is with refs outside
+                * heads or tags, and did not specify the pattern
+                * in full (e.g. "refs/remotes/origin/master") or at
+                * least from the toplevel (e.g. "remotes/origin/master");
+                * otherwise "git push $URL master" would result in
+                * ambiguity between remotes/origin/master and heads/master
+                * at the remote site.
+                */
+               if (namelen != patlen &&
+                   patlen != namelen - 5 &&
+                   strncmp(name, "refs/heads/", 11) &&
+                   strncmp(name, "refs/tags/", 10)) {
+                       /* We want to catch the case where only weak
+                        * matches are found and there are multiple
+                        * matches, and where more than one strong
+                        * matches are found, as ambiguous.  One
+                        * strong match with zero or more weak matches
+                        * are acceptable as a unique match.
+                        */
+                       matched_weak = refs;
+                       weak_match++;
+               }
+               else {
+                       matched = refs;
+                       match++;
+               }
+       }
+       if (!matched) {
+               *matched_ref = matched_weak;
+               return weak_match;
+       }
+       else {
+               *matched_ref = matched;
+               return match;
        }
-       return match;
 }
 
 static void link_dst_tail(struct ref *ref, struct ref ***tail)
@@ -203,6 +241,13 @@ static struct ref *try_explicit_object_name(const char *name)
        unsigned char sha1[20];
        struct ref *ref;
        int len;
+
+       if (!*name) {
+               ref = xcalloc(1, sizeof(*ref) + 20);
+               strcpy(ref->name, "(delete)");
+               hashclr(ref->new_sha1);
+               return ref;
+       }
        if (get_sha1(name, sha1))
                return NULL;
        len = strlen(name) + 1;
@@ -225,7 +270,8 @@ static int match_explicit_refs(struct ref *src, struct ref *dst,
                        break;
                case 0:
                        /* The source could be in the get_sha1() format
-                        * not a reference name.
+                        * not a reference name.  :refs/other is a
+                        * way to delete 'other' ref at the remote end.
                         */
                        matched_src = try_explicit_object_name(rs[i].src);
                        if (matched_src)
@@ -599,12 +645,19 @@ static void git_proxy_connect(int fd[2], char *host)
        close(pipefd[1][0]);
 }
 
+#define MAX_CMD_LEN 1024
+
 /*
- * Yeah, yeah, fixme. Need to pass in the heads etc.
+ * This returns 0 if the transport protocol does not need fork(2),
+ * or a process id if it does.  Once done, finish the connection
+ * with finish_connect() with the value returned from this function
+ * (it is safe to call finish_connect() with 0 to support the former
+ * case).
+ *
+ * Does not return a negative value on error; it just dies.
  */
-int git_connect(int fd[2], char *url, const char *prog)
+pid_t git_connect(int fd[2], char *url, const char *prog)
 {
-       char command[1024];
        char *host, *path = url;
        char *end;
        int c;
@@ -697,8 +750,18 @@ int git_connect(int fd[2], char *url, const char *prog)
        if (pid < 0)
                die("unable to fork");
        if (!pid) {
-               snprintf(command, sizeof(command), "%s %s", prog,
-                        sq_quote(path));
+               char command[MAX_CMD_LEN];
+               char *posn = command;
+               int size = MAX_CMD_LEN;
+               int of = 0;
+
+               of |= add_to_string(&posn, &size, prog, 0);
+               of |= add_to_string(&posn, &size, " ", 0);
+               of |= add_to_string(&posn, &size, path, 1);
+
+               if (of)
+                       die("command line too long");
+
                dup2(pipefd[1][0], 0);
                dup2(pipefd[0][1], 1);
                close(pipefd[0][0]);
@@ -737,6 +800,9 @@ int git_connect(int fd[2], char *url, const char *prog)
 
 int finish_connect(pid_t pid)
 {
+       if (pid == 0)
+               return 0;
+
        while (waitpid(pid, NULL, 0) < 0) {
                if (errno != EINTR)
                        return -1;