format-patch: improve head calculation for cover-letter

diff --git a/setup.c b/setup.c
index a2be9690ad3bd8895affe485e67bb7edac4afa9d..94c1e61bda747ed5c664bbbf8431234dc8276d29 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -525,6 +525,12 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
                        set_git_work_tree(core_worktree);
                }
        }
+       else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
+               /* #16d */
+               set_git_dir(gitdirenv);
+               free(gitfile);
+               return NULL;
+       }
        else /* #2, #10 */
                set_git_work_tree(".");
 
@@ -603,6 +609,8 @@ static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongi
        if (check_repository_format_gently(".", nongit_ok))
                return NULL;
 
+       setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
+
        /* --work-tree is set without --git-dir; use discovered one */
        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
                const char *gitdir;
@@ -796,9 +804,9 @@ const char *setup_git_directory_gently(int *nongit_ok)
 
        prefix = setup_git_directory_gently_1(nongit_ok);
        if (prefix)
-               setenv("GIT_PREFIX", prefix, 1);
+               setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
        else
-               setenv("GIT_PREFIX", "", 1);
+               setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 
        if (startup_info) {
                startup_info->have_repository = !nongit_ok || !*nongit_ok;