setup_git_directory: delay core.bare/core.worktree errors

If both core.bare and core.worktree are set, we complain
about the bogus config and die. Dying is good, because it
avoids commands running and doing damage in a potentially
incorrect setup. But dying _there_ is bad, because it means
that commands which do not even care about the work tree
cannot run. This can make repairing the situation harder:

  [setup]
  $ git config core.bare true
  $ git config core.worktree /some/path

  [OK, expected.]
  $ git status
  fatal: core.bare and core.worktree do not make sense

  [Hrm...]
  $ git config --unset core.worktree
  fatal: core.bare and core.worktree do not make sense

  [Nope...]
  $ git config --edit
  fatal: core.bare and core.worktree do not make sense

  [Gaaah.]
  $ git help config
  fatal: core.bare and core.worktree do not make sense

Instead, let's issue a warning about the bogus config when
we notice it (i.e., for all commands), but only die when the
command tries to use the work tree (by calling setup_work_tree).
So we now get:

  $ git status
  warning: core.bare and core.worktree do not make sense
  fatal: unable to set up work tree using invalid config

  $ git config --unset core.worktree
  warning: core.bare and core.worktree do not make sense

We have to update t1510 to accomodate this; it uses
symbolic-ref to check whether the configuration works or
not, but of course that command does not use the working
tree. Instead, we switch it to use `git status`, as it
requires a work-tree, does not need any special setup, and
is read-only (so a failure will not adversely affect further
tests).

In addition, we add a new test that checks the desired
behavior (i.e., that running "git config" with the bogus
config does in fact work).

Reported-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/setup.c b/setup.c
index 979b13f..9c32aae 100644
--- a/setup.c
+++ b/setup.c
@@ -4,6 +4,7 @@
 
 static int inside_git_dir = -1;
 static int inside_work_tree = -1;
+static int work_tree_config_is_bogus;
 
 /*
  * The input parameter must contain an absolute path, and it must already be
@@ -286,6 +287,10 @@ void setup_work_tree(void)
 
 	if (initialized)
 		return;
+
+	if (work_tree_config_is_bogus)
+		die("unable to set up work tree using invalid config");
+
 	work_tree = get_git_work_tree();
 	git_dir = get_git_dir();
 	if (!is_absolute_path(git_dir))
@@ -422,8 +427,11 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	if (work_tree_env)
 		set_git_work_tree(work_tree_env);
 	else if (is_bare_repository_cfg > 0) {
-		if (git_work_tree_cfg) /* #22.2, #30 */
-			die("core.bare and core.worktree do not make sense");
+		if (git_work_tree_cfg) {
+			/* #22.2, #30 */
+			warning("core.bare and core.worktree do not make sense");
+			work_tree_config_is_bogus = 1;
+		}
 
 		/* #18, #26 */
 		set_git_dir(gitdirenv);