Documentation: Describe other situations where -z affects git diff

diff --git a/lockfile.c b/lockfile.c
index 6d756086939b631ab13bf4fcdb8deed2787eed6b..b0d74cdddee2407de590cb9f725e8e24093d9d35 100644 (file)
--- a/lockfile.c
+++ b/lockfile.c
@@ -2,6 +2,7 @@
  * Copyright (c) 2005, Junio C Hamano
  */
 #include "cache.h"
+#include "sigchain.h"
 
 static struct lock_file *lock_file_list;
 static const char *alternate_index_output;
@@ -15,7 +16,7 @@ static void remove_lock_file(void)
                    lock_file_list->filename[0]) {
                        if (lock_file_list->fd >= 0)
                                close(lock_file_list->fd);
-                       unlink(lock_file_list->filename);
+                       unlink_or_warn(lock_file_list->filename);
                }
                lock_file_list = lock_file_list->next;
        }
@@ -24,7 +25,7 @@ static void remove_lock_file(void)
 static void remove_lock_file_on_signal(int signo)
 {
        remove_lock_file();
-       signal(signo, SIG_DFL);
+       sigchain_pop(signo);
        raise(signo);
 }
 
@@ -108,7 +109,7 @@ static char *resolve_symlink(char *p, size_t s)
                         * link is a relative path, so I must replace the
                         * last element of p with it.
                         */
-                       char *r = (char*)last_path_elm(p);
+                       char *r = (char *)last_path_elm(p);
                        if (r - p + link_len < s)
                                strcpy(r, link);
                        else {
@@ -136,10 +137,7 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
        lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
        if (0 <= lk->fd) {
                if (!lock_file_list) {
-                       signal(SIGINT, remove_lock_file_on_signal);
-                       signal(SIGHUP, remove_lock_file_on_signal);
-                       signal(SIGTERM, remove_lock_file_on_signal);
-                       signal(SIGQUIT, remove_lock_file_on_signal);
+                       sigchain_push_common(remove_lock_file_on_signal);
                        atexit(remove_lock_file);
                }
                lk->owner = getpid();
@@ -157,11 +155,40 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
        return lk->fd;
 }
 
+static char *unable_to_lock_message(const char *path, int err)
+{
+       struct strbuf buf = STRBUF_INIT;
+
+       if (err == EEXIST) {
+               strbuf_addf(&buf, "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.",
+                           make_nonrelative_path(path), strerror(err));
+       } else
+               strbuf_addf(&buf, "Unable to create '%s.lock': %s",
+                           make_nonrelative_path(path), strerror(err));
+       return strbuf_detach(&buf, NULL);
+}
+
+int unable_to_lock_error(const char *path, int err)
+{
+       char *msg = unable_to_lock_message(path, err);
+       error("%s", msg);
+       free(msg);
+       return -1;
+}
+
+NORETURN void unable_to_lock_index_die(const char *path, int err)
+{
+       die("%s", unable_to_lock_message(path, err));
+}
+
 int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags)
 {
        int fd = lock_file(lk, path, flags);
        if (fd < 0 && (flags & LOCK_DIE_ON_ERROR))
-               die("unable to create '%s.lock': %s", path, strerror(errno));
+               unable_to_lock_index_die(path, errno);
        return fd;
 }
 
@@ -172,7 +199,7 @@ int hold_lock_file_for_append(struct lock_file *lk, const char *path, int flags)
        fd = lock_file(lk, path, flags);
        if (fd < 0) {
                if (flags & LOCK_DIE_ON_ERROR)
-                       die("unable to create '%s.lock': %s", path, strerror(errno));
+                       unable_to_lock_index_die(path, errno);
                return fd;
        }
 
@@ -247,7 +274,7 @@ void rollback_lock_file(struct lock_file *lk)
        if (lk->filename[0]) {
                if (lk->fd >= 0)
                        close(lk->fd);
-               unlink(lk->filename);
+               unlink_or_warn(lk->filename);
        }
        lk->filename[0] = 0;
 }