setup: split off get_device_or_die helper

This does not eliminate any code, but it skims some off of
the main loop of setup_git_directory_gently so that can be
understood more easily.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/setup.c b/setup.c
index 9fc05e2c0a79df1faf313994430d0649f8231d9a..5fb9c54ba6b21aab62b76602500ae2c408f9216d 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -388,6 +388,16 @@ static const char *setup_nongit(const char *cwd, int *nongit_ok)
        return NULL;
 }
 
+static dev_t get_device_or_die(const char *path, const char *prefix)
+{
+       struct stat buf;
+       if (stat(path, &buf))
+               die_errno("failed to stat '%s%s%s'",
+                               prefix ? prefix : "",
+                               prefix ? "/" : "", path);
+       return buf.st_dev;
+}
+
 /*
  * We cannot decide in this function whether we are in the work tree or
  * not, since the config can only be read _after_ this function was called.
@@ -402,7 +412,6 @@ const char *setup_git_directory_gently(int *nongit_ok)
        int len, offset, ceil_offset, root_len;
        dev_t current_device = 0;
        int one_filesystem = 1;
-       struct stat buf;
 
        /*
         * Let's assume that we are in a git repository.
@@ -441,11 +450,8 @@ const char *setup_git_directory_gently(int *nongit_ok)
         */
        offset = len = strlen(cwd);
        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
-       if (one_filesystem) {
-               if (stat(".", &buf))
-                       die_errno("failed to stat '.'");
-               current_device = buf.st_dev;
-       }
+       if (one_filesystem)
+               current_device = get_device_or_die(".", NULL);
        for (;;) {
                if (cwd_contains_git_dir(&gitfile_dir))
                        break;
@@ -456,11 +462,8 @@ const char *setup_git_directory_gently(int *nongit_ok)
                if (offset <= ceil_offset)
                        return setup_nongit(cwd, nongit_ok);
                if (one_filesystem) {
-                       if (stat("..", &buf)) {
-                               cwd[offset] = '\0';
-                               die_errno("failed to stat '%s/..'", cwd);
-                       }
-                       if (buf.st_dev != current_device) {
+                       dev_t parent_device = get_device_or_die("..", cwd);
+                       if (parent_device != current_device) {
                                if (nongit_ok) {
                                        if (chdir(cwd))
                                                die_errno("Cannot come back to cwd");