git-pull: allow pulling into an empty repository

diff --git a/fetch-pack.c b/fetch-pack.c
index 99ac08b2c2528358d51665ef3f301cd68947409c..0a169dce8574102a03c978bb24f8d0664f1fc9b6 100644 (file)
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -3,6 +3,9 @@
 #include "pkt-line.h"
 #include "commit.h"
 #include "tag.h"
+#include "exec_cmd.h"
+#include "sideband.h"
+#include <sys/wait.h>
 
 static int keep_pack;
 static int quiet;
@@ -166,12 +169,13 @@ static int find_common(int fd[2], unsigned char *result_sha1,
                }
 
                if (!fetching)
-                       packet_write(fd[1], "want %s%s%s%s%s\n",
+                       packet_write(fd[1], "want %s%s%s%s%s%s\n",
                                     sha1_to_hex(remote),
                                     (multi_ack ? " multi_ack" : ""),
                                     (use_sideband == 2 ? " side-band-64k" : ""),
                                     (use_sideband == 1 ? " side-band" : ""),
-                                    (use_thin_pack ? " thin-pack" : ""));
+                                    (use_thin_pack ? " thin-pack" : ""),
+                                    " ofs-delta");
                else
                        packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
                fetching++;
@@ -415,6 +419,103 @@ static int everything_local(struct ref **refs, int nr_match, char **match)
        return retval;
 }
 
+static pid_t setup_sideband(int fd[2], int xd[2])
+{
+       pid_t side_pid;
+
+       if (!use_sideband) {
+               fd[0] = xd[0];
+               fd[1] = xd[1];
+               return 0;
+       }
+       /* xd[] is talking with upload-pack; subprocess reads from
+        * xd[0], spits out band#2 to stderr, and feeds us band#1
+        * through our fd[0].
+        */
+       if (pipe(fd) < 0)
+               die("fetch-pack: unable to set up pipe");
+       side_pid = fork();
+       if (side_pid < 0)
+               die("fetch-pack: unable to fork off sideband demultiplexer");
+       if (!side_pid) {
+               /* subprocess */
+               close(fd[0]);
+               if (xd[0] != xd[1])
+                       close(xd[1]);
+               if (recv_sideband("fetch-pack", xd[0], fd[1], 2))
+                       exit(1);
+               exit(0);
+       }
+       close(xd[0]);
+       close(fd[1]);
+       fd[1] = xd[1];
+       return side_pid;
+}
+
+static int get_pack(int xd[2], const char **argv)
+{
+       int status;
+       pid_t pid, side_pid;
+       int fd[2];
+
+       side_pid = setup_sideband(fd, xd);
+       pid = fork();
+       if (pid < 0)
+               die("fetch-pack: unable to fork off %s", argv[0]);
+       if (!pid) {
+               dup2(fd[0], 0);
+               close(fd[0]);
+               close(fd[1]);
+               execv_git_cmd(argv);
+               die("%s exec failed", argv[0]);
+       }
+       close(fd[0]);
+       close(fd[1]);
+       while (waitpid(pid, &status, 0) < 0) {
+               if (errno != EINTR)
+                       die("waiting for %s: %s", argv[0], strerror(errno));
+       }
+       if (WIFEXITED(status)) {
+               int code = WEXITSTATUS(status);
+               if (code)
+                       die("%s died with error code %d", argv[0], code);
+               return 0;
+       }
+       if (WIFSIGNALED(status)) {
+               int sig = WTERMSIG(status);
+               die("%s died of signal %d", argv[0], sig);
+       }
+       die("%s died of unnatural causes %d", argv[0], status);
+}
+
+static int explode_rx_pack(int xd[2])
+{
+       const char *argv[3] = { "unpack-objects", quiet ? "-q" : NULL, NULL };
+       return get_pack(xd, argv);
+}
+
+static int keep_rx_pack(int xd[2])
+{
+       const char *argv[6];
+       char keep_arg[256];
+       int n = 0;
+
+       argv[n++] = "index-pack";
+       argv[n++] = "--stdin";
+       if (!quiet)
+               argv[n++] = "-v";
+       if (use_thin_pack)
+               argv[n++] = "--fix-thin";
+       if (keep_pack > 1) {
+               int s = sprintf(keep_arg, "--keep=fetch-pack %i on ", getpid());
+               if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+                       strcpy(keep_arg + s, "localhost");
+               argv[n++] = keep_arg;
+       }
+       argv[n] = NULL;
+       return get_pack(xd, argv);
+}
+
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
        struct ref *ref;
@@ -446,17 +547,13 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
                goto all_done;
        }
        if (find_common(fd, sha1, ref) < 0)
-               if (!keep_pack)
+               if (keep_pack != 1)
                        /* When cloning, it is not unusual to have
                         * no common commit.
                         */
                        fprintf(stderr, "warning: no common commits\n");
 
-       if (keep_pack)
-               status = receive_keep_pack(fd, "git-fetch-pack", quiet, use_sideband);
-       else
-               status = receive_unpack_pack(fd, "git-fetch-pack", quiet, use_sideband);
-
+       status = (keep_pack) ? keep_rx_pack(fd) : explode_rx_pack(fd);
        if (status)
                die("git-fetch-pack: fetch failed.");
 
@@ -493,7 +590,7 @@ int main(int argc, char **argv)
                                continue;
                        }
                        if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
-                               keep_pack = 1;
+                               keep_pack++;
                                continue;
                        }
                        if (!strcmp("--thin", arg)) {
@@ -517,8 +614,6 @@ int main(int argc, char **argv)
        }
        if (!dest)
                usage(fetch_pack_usage);
-       if (keep_pack)
-               use_thin_pack = 0;
        pid = git_connect(fd, dest, exec);
        if (pid < 0)
                return 1;