git-pull: allow pulling into an empty repository

[git.git] / receive-pack.c

diff --git a/receive-pack.c b/receive-pack.c
index b8d12700d80254e59ee8f1b017f19a465dfeccb7..d56898c9b29d3e5ea01fd5a211790141d0beac21 100644 (file)
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -3,8 +3,10 @@
 #include "refs.h"
 #include "pkt-line.h"
 #include "run-command.h"
+#include "exec_cmd.h"
 #include "commit.h"
 #include "object.h"
+#include <sys/wait.h>
 
 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
 
@@ -251,12 +253,13 @@ static const char *parse_pack_header(struct pack_header *hdr)
        return NULL;
 }
 
+static const char *pack_lockfile;
+
 static const char *unpack(void)
 {
        struct pack_header hdr;
        const char *hdr_err;
        char hdr_arg[38];
-       int code;
 
        hdr_err = parse_pack_header(&hdr);
        if (hdr_err)
@@ -265,33 +268,13 @@ static const char *unpack(void)
                        ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 
        if (ntohl(hdr.hdr_entries) < unpack_limit) {
+               int code;
                const char *unpacker[3];
                unpacker[0] = "unpack-objects";
                unpacker[1] = hdr_arg;
                unpacker[2] = NULL;
                code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
-       } else {
-               const char *keeper[6];
-               char my_host[255], keep_arg[128 + 255];
-
-               if (gethostname(my_host, sizeof(my_host)))
-                       strcpy(my_host, "localhost");
-               snprintf(keep_arg, sizeof(keep_arg),
-                               "--keep=receive-pack %i on %s",
-                               getpid(), my_host);
-
-               keeper[0] = "index-pack";
-               keeper[1] = "--stdin";
-               keeper[2] = "--fix-thin";
-               keeper[3] = hdr_arg;
-               keeper[4] = keep_arg;
-               keeper[5] = NULL;
-               code = run_command_v_opt(1, keeper, RUN_GIT_CMD);
-               if (!code)
-                       reprepare_packed_git();
-       }
-
-       switch (code) {
+               switch (code) {
                case 0:
                        return NULL;
                case -ERR_RUN_COMMAND_FORK:
@@ -308,6 +291,71 @@ static const char *unpack(void)
                        return "unpacker died strangely";
                default:
                        return "unpacker exited with error code";
+               }
+       } else {
+               const char *keeper[6];
+               int fd[2], s, len, status;
+               pid_t pid;
+               char keep_arg[256];
+               char packname[46];
+
+               s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
+               if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+                       strcpy(keep_arg + s, "localhost");
+
+               keeper[0] = "index-pack";
+               keeper[1] = "--stdin";
+               keeper[2] = "--fix-thin";
+               keeper[3] = hdr_arg;
+               keeper[4] = keep_arg;
+               keeper[5] = NULL;
+
+               if (pipe(fd) < 0)
+                       return "index-pack pipe failed";
+               pid = fork();
+               if (pid < 0)
+                       return "index-pack fork failed";
+               if (!pid) {
+                       dup2(fd[1], 1);
+                       close(fd[1]);
+                       close(fd[0]);
+                       execv_git_cmd(keeper);
+                       die("execv of index-pack failed");
+               }
+               close(fd[1]);
+
+               /*
+                * The first thing we expects from index-pack's output
+                * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
+                * %40s is the newly created pack SHA1 name.  In the "keep"
+                * case, we need it to remove the corresponding .keep file
+                * later on.  If we don't get that then tough luck with it.
+                */
+               for (len = 0;
+                    len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
+                    len += s);
+               close(fd[0]);
+               if (len == 46 && packname[45] == '\n' &&
+                   memcmp(packname, "keep\t", 5) == 0) {
+                       char path[PATH_MAX];
+                       packname[45] = 0;
+                       snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
+                                get_object_directory(), packname + 5);
+                       pack_lockfile = xstrdup(path);
+               }
+
+               /* Then wrap our index-pack process. */
+               while (waitpid(pid, &status, 0) < 0)
+                       if (errno != EINTR)
+                               return "waitpid failed";
+               if (WIFEXITED(status)) {
+                       int code = WEXITSTATUS(status);
+                       if (code)
+                               return "index-pack exited with error code";
+                       reprepare_packed_git();
+                       return NULL;
+               }
+               return "index-pack abnormal exit";
        }
 }
 
@@ -363,6 +411,8 @@ int main(int argc, char **argv)
                const char *unpack_status = unpack();
                if (!unpack_status)
                        execute_commands();
+               if (pack_lockfile)
+                       unlink(pack_lockfile);
                if (report_status)
                        report(unpack_status);
        }