More friendly message when locking the index fails.

diff --git a/lockfile.c b/lockfile.c
index 4023797b00fe21ecbabe3407ef8a12fca0690607..8e556ff8c9671864db44dc8b6f4a861bd35142a6 100644 (file)
--- a/lockfile.c
+++ b/lockfile.c
@@ -121,15 +121,17 @@ static char *resolve_symlink(char *p, size_t s)
 }
 
 
-static int lock_file(struct lock_file *lk, const char *path)
+static int lock_file(struct lock_file *lk, const char *path, int flags)
 {
-       if (strlen(path) >= sizeof(lk->filename)) return -1;
+       if (strlen(path) >= sizeof(lk->filename))
+               return -1;
        strcpy(lk->filename, path);
        /*
         * subtract 5 from size to make sure there's room for adding
         * ".lock" for the lock file name
         */
-       resolve_symlink(lk->filename, sizeof(lk->filename)-5);
+       if (!(flags & LOCK_NODEREF))
+               resolve_symlink(lk->filename, sizeof(lk->filename)-5);
        strcat(lk->filename, ".lock");
        lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
        if (0 <= lk->fd) {
@@ -138,6 +140,7 @@ static int lock_file(struct lock_file *lk, const char *path)
                        signal(SIGHUP, remove_lock_file_on_signal);
                        signal(SIGTERM, remove_lock_file_on_signal);
                        signal(SIGQUIT, remove_lock_file_on_signal);
+                       signal(SIGPIPE, remove_lock_file_on_signal);
                        atexit(remove_lock_file);
                }
                lk->owner = getpid();
@@ -155,21 +158,35 @@ static int lock_file(struct lock_file *lk, const char *path)
        return lk->fd;
 }
 
-int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
+
+NORETURN void unable_to_lock_index_die(const char *path, int err)
+{
+       if (errno == EEXIST) {
+               die("Unable to create '%s.lock': %s.\n\n"
+                   "If no other git process is currently running, this probably means a\n"
+                   "git process crashed in this repository earlier. Make sure no other git\n"
+                   "process is running and remove the file manually to continue.",
+                   path, strerror(err));
+       } else {
+               die("Unable to create '%s.lock': %s", path, strerror(err));
+       }
+}
+
+int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags)
 {
-       int fd = lock_file(lk, path);
-       if (fd < 0 && die_on_error)
-               die("unable to create '%s.lock': %s", path, strerror(errno));
+       int fd = lock_file(lk, path, flags);
+       if (fd < 0 && (flags & LOCK_DIE_ON_ERROR))
+               unable_to_lock_index_die(path, errno);
        return fd;
 }
 
-int hold_lock_file_for_append(struct lock_file *lk, const char *path, int die_on_error)
+int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags)
 {
        int fd, orig_fd;
 
-       fd = lock_file(lk, path);
+       fd = lock_file(lk, path, flags);
        if (fd < 0) {
-               if (die_on_error)
+               if (flags & LOCK_DIE_ON_ERROR)
                        die("unable to create '%s.lock': %s", path, strerror(errno));
                return fd;
        }
@@ -177,13 +194,13 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int die_on
        orig_fd = open(path, O_RDONLY);
        if (orig_fd < 0) {
                if (errno != ENOENT) {
-                       if (die_on_error)
+                       if (flags & LOCK_DIE_ON_ERROR)
                                die("cannot open '%s' for copying", path);
                        close(fd);
                        return error("cannot open '%s' for copying", path);
                }
        } else if (copy_fd(orig_fd, fd)) {
-               if (die_on_error)
+               if (flags & LOCK_DIE_ON_ERROR)
                        exit(128);
                close(fd);
                return -1;
@@ -215,7 +232,10 @@ int commit_lock_file(struct lock_file *lk)
 
 int hold_locked_index(struct lock_file *lk, int die_on_error)
 {
-       return hold_lock_file_for_update(lk, get_index_file(), die_on_error);
+       return hold_lock_file_for_update(lk, get_index_file(),
+                                        die_on_error
+                                        ? LOCK_DIE_ON_ERROR
+                                        : 0);
 }
 
 void set_alternate_index_output(const char *name)