Fix off-by-one error in git-merge
[gitweb.git] / send-pack.c
index af57d402862c4d0572612b3e53e304978c35b352..55d8ff7e102fa6cc369c993035c0579c2d33b775 100644 (file)
 #include "cache.h"
+#include "commit.h"
+#include "tag.h"
+#include "refs.h"
+#include "pkt-line.h"
 
-static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
-
+static const char send_pack_usage[] =
+"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
+"  --all and explicit <head> specification are mutually exclusive.";
 static const char *exec = "git-receive-pack";
+static int send_all = 0;
+static int force_update = 0;
 
-static int send_pack(int in, int out)
+static int is_zero_sha1(const unsigned char *sha1)
 {
-       for (;;) {
-               static char buffer[1000];
-               int ret = read(in, buffer, sizeof(buffer));
-               if (ret > 0) {
-                       write(1, buffer, ret);
-                       continue;
+       int i;
+
+       for (i = 0; i < 20; i++) {
+               if (*sha1++)
+                       return 0;
+       }
+       return 1;
+}
+
+static void exec_pack_objects(void)
+{
+       static char *args[] = {
+               "git-pack-objects",
+               "--stdout",
+               NULL
+       };
+       execvp("git-pack-objects", args);
+       die("git-pack-objects exec failed (%s)", strerror(errno));
+}
+
+static void exec_rev_list(struct ref *refs)
+{
+       static char *args[1000];
+       int i = 0;
+
+       args[i++] = "git-rev-list";     /* 0 */
+       args[i++] = "--objects";        /* 1 */
+       while (refs) {
+               char *buf = malloc(100);
+               if (i > 900)
+                       die("git-rev-list environment overflow");
+               if (!is_zero_sha1(refs->old_sha1) &&
+                   has_sha1_file(refs->old_sha1)) {
+                       args[i++] = buf;
+                       snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
+                       buf += 50;
                }
-               break;
+               if (!is_zero_sha1(refs->new_sha1)) {
+                       args[i++] = buf;
+                       snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
+               }
+               refs = refs->next;
        }
-       close(out);
+       args[i] = NULL;
+       execvp("git-rev-list", args);
+       die("git-rev-list exec failed (%s)", strerror(errno));
+}
+
+static void rev_list(int fd, struct ref *refs)
+{
+       int pipe_fd[2];
+       pid_t pack_objects_pid;
+
+       if (pipe(pipe_fd) < 0)
+               die("rev-list setup: pipe failed");
+       pack_objects_pid = fork();
+       if (!pack_objects_pid) {
+               dup2(pipe_fd[0], 0);
+               dup2(fd, 1);
+               close(pipe_fd[0]);
+               close(pipe_fd[1]);
+               close(fd);
+               exec_pack_objects();
+               die("pack-objects setup failed");
+       }
+       if (pack_objects_pid < 0)
+               die("pack-objects fork failed");
+       dup2(pipe_fd[1], 1);
+       close(pipe_fd[0]);
+       close(pipe_fd[1]);
+       close(fd);
+       exec_rev_list(refs);
+}
+
+static int pack_objects(int fd, struct ref *refs)
+{
+       pid_t rev_list_pid;
+
+       rev_list_pid = fork();
+       if (!rev_list_pid) {
+               rev_list(fd, refs);
+               die("rev-list setup failed");
+       }
+       if (rev_list_pid < 0)
+               die("rev-list fork failed");
+       /*
+        * We don't wait for the rev-list pipeline in the parent:
+        * we end up waiting for the other end instead
+        */
        return 0;
 }
 
-/*
- * First, make it shell-safe.  We do this by just disallowing any
- * special characters. Somebody who cares can do escaping and let
- * through the rest. But since we're doing to feed this to ssh as
- * a command line, we're going to be pretty damn anal for now.
- */
-static char *shell_safe(char *url)
+static void unmark_and_free(struct commit_list *list, unsigned int mark)
 {
-       char *n = url;
-       unsigned char c;
-       static const char flags[256] = {
-               ['0'...'9'] = 1,
-               ['a'...'z'] = 1,
-               ['A'...'Z'] = 1,
-               ['.'] = 1, ['/'] = 1,
-               ['-'] = 1, ['+'] = 1,
-               [':'] = 1
-       };
+       while (list) {
+               struct commit_list *temp = list;
+               temp->item->object.flags &= ~mark;
+               list = temp->next;
+               free(temp);
+       }
+}
+
+static int ref_newer(const unsigned char *new_sha1,
+                    const unsigned char *old_sha1)
+{
+       struct object *o;
+       struct commit *old, *new;
+       struct commit_list *list, *used;
+       int found = 0;
 
-       while ((c = *n++) != 0) {
-               if (flags[c] != 1)
-                       die("I don't like '%c'. Sue me.", c);
+       /* Both new and old must be commit-ish and new is descendant of
+        * old.  Otherwise we require --force.
+        */
+       o = deref_tag(parse_object(old_sha1));
+       if (!o || o->type != commit_type)
+               return 0;
+       old = (struct commit *) o;
+
+       o = deref_tag(parse_object(new_sha1));
+       if (!o || o->type != commit_type)
+               return 0;
+       new = (struct commit *) o;
+
+       if (parse_commit(new) < 0)
+               return 0;
+
+       used = list = NULL;
+       commit_list_insert(new, &list);
+       while (list) {
+               new = pop_most_recent_commit(&list, 1);
+               commit_list_insert(new, &used);
+               if (new == old) {
+                       found = 1;
+                       break;
+               }
        }
-       return url;
+       unmark_and_free(list, 1);
+       unmark_and_free(used, 1);
+       return found;
 }
 
-/*
- * Yeah, yeah, fixme. Need to pass in the heads etc.
- */
-static int setup_connection(int fd[2], char *url, char **heads)
+static struct ref *local_refs, **local_tail;
+static struct ref *remote_refs, **remote_tail;
+
+static int one_local_ref(const char *refname, const unsigned char *sha1)
+{
+       struct ref *ref;
+       int len = strlen(refname) + 1;
+       ref = xcalloc(1, sizeof(*ref) + len);
+       memcpy(ref->new_sha1, sha1, 20);
+       memcpy(ref->name, refname, len);
+       *local_tail = ref;
+       local_tail = &ref->next;
+       return 0;
+}
+
+static void get_local_heads(void)
 {
-       char command[1024];
-       const char *host, *path;
-       char *colon;
-       int pipefd[2][2];
-
-       url = shell_safe(url);
-       host = NULL;
-       path = url;
-       colon = strchr(url, ':');
-       if (colon) {
-               *colon = 0;
-               host = url;
-               path = colon+1;
+       local_tail = &local_refs;
+       for_each_ref(one_local_ref);
+}
+
+static int send_pack(int in, int out, int nr_refspec, char **refspec)
+{
+       struct ref *ref;
+       int new_refs;
+
+       /* No funny business with the matcher */
+       remote_tail = get_remote_heads(in, &remote_refs, 0, NULL);
+       get_local_heads();
+
+       /* match them up */
+       if (!remote_tail)
+               remote_tail = &remote_refs;
+       if (match_refs(local_refs, remote_refs, &remote_tail,
+                      nr_refspec, refspec, send_all))
+               return -1;
+       /*
+        * Finally, tell the other end!
+        */
+       new_refs = 0;
+       for (ref = remote_refs; ref; ref = ref->next) {
+               char old_hex[60], *new_hex;
+               if (!ref->peer_ref)
+                       continue;
+               if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
+                       fprintf(stderr, "'%s': up-to-date\n", ref->name);
+                       continue;
+               }
+
+               /* This part determines what can overwrite what.
+                * The rules are:
+                *
+                * (0) you can always use --force or +A:B notation to
+                *     selectively force individual ref pairs.
+                *
+                * (1) if the old thing does not exist, it is OK.
+                *
+                * (2) if you do not have the old thing, you are not allowed
+                *     to overwrite it; you would not know what you are losing
+                *     otherwise.
+                *
+                * (3) if both new and old are commit-ish, and new is a
+                *     descendant of old, it is OK.
+                */
+
+               if (!force_update &&
+                   !is_zero_sha1(ref->old_sha1) &&
+                   !ref->force) {
+                       if (!has_sha1_file(ref->old_sha1)) {
+                               error("remote '%s' object %s does not "
+                                     "exist on local",
+                                     ref->name, sha1_to_hex(ref->old_sha1));
+                               continue;
+                       }
+
+                       /* We assume that local is fsck-clean.  Otherwise
+                        * you _could_ have an old tag which points at
+                        * something you do not have, which may or may not
+                        * be a commit.
+                        */
+                       if (!ref_newer(ref->peer_ref->new_sha1,
+                                      ref->old_sha1)) {
+                               error("remote ref '%s' is not a strict "
+                                     "subset of local ref '%s'.", ref->name,
+                                     ref->peer_ref->name);
+                               continue;
+                       }
+               }
+               memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
+               if (is_zero_sha1(ref->new_sha1)) {
+                       error("cannot happen anymore");
+                       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);
+               fprintf(stderr, "updating '%s'", ref->name);
+               if (strcmp(ref->name, ref->peer_ref->name))
+                       fprintf(stderr, " using '%s'", ref->peer_ref->name);
+               fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
        }
-       snprintf(command, sizeof(command), "%s %s", exec, path);
-       if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
-               die("unable to create pipe pair for communication");
-       if (!fork()) {
-               dup2(pipefd[1][0], 0);
-               dup2(pipefd[0][1], 1);
-               close(pipefd[0][0]);
-               close(pipefd[0][1]);
-               close(pipefd[1][0]);
-               close(pipefd[1][1]);
-               if (host)
-                       execlp("ssh", "ssh", host, command, NULL);
-               else
-                       execlp(host, command, NULL);
-               die("exec failed");
-       }               
-       fd[0] = pipefd[0][0];
-       fd[1] = pipefd[1][1];
-       close(pipefd[0][1]);
-       close(pipefd[1][0]);
+
+       packet_flush(out);
+       if (new_refs)
+               pack_objects(out, remote_refs);
+       close(out);
        return 0;
 }
 
+
 int main(int argc, char **argv)
 {
        int i, nr_heads = 0;
        char *dest = NULL;
        char **heads = NULL;
-       int fd[2];
+       int fd[2], ret;
+       pid_t pid;
 
        argv++;
-       for (i = 1; i < argc; i++) {
-               char *arg = *argv++;
+       for (i = 1; i < argc; i++, argv++) {
+               char *arg = *argv;
 
                if (*arg == '-') {
                        if (!strncmp(arg, "--exec=", 7)) {
                                exec = arg + 7;
                                continue;
                        }
+                       if (!strcmp(arg, "--all")) {
+                               send_all = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--force")) {
+                               force_update = 1;
+                               continue;
+                       }
                        usage(send_pack_usage);
                }
-               dest = arg;
+               if (!dest) {
+                       dest = arg;
+                       continue;
+               }
                heads = argv;
-               nr_heads = argc - i -1;
+               nr_heads = argc - i;
                break;
        }
        if (!dest)
                usage(send_pack_usage);
-       if (setup_connection(fd, dest, heads))
+       if (heads && send_all)
+               usage(send_pack_usage);
+       pid = git_connect(fd, dest, exec);
+       if (pid < 0)
                return 1;
-       return send_pack(fd[0], fd[1]);
+       ret = send_pack(fd[0], fd[1], nr_heads, heads);
+       close(fd[0]);
+       close(fd[1]);
+       finish_connect(pid);
+       return ret;
 }