config: treat non-existent config files as empty

The git_config() function signals error by returning -1 in
two instances:

  1. An actual error occurs in opening a config file (parse
     errors cause an immediate die).

  2. Of the three possible config files, none was found.

However, this second case is often not an error at all; it
simply means that the user has no configuration (they are
outside a repo, and they have no ~/.gitconfig file). This
can lead to confusing errors, such as when the bash
completion calls "git config --list" outside of a repo. If
the user has a ~/.gitconfig, the command completes
succesfully; if they do not, it complains to stderr.

This patch allows callers of git_config to distinguish
between the two cases. Error is signaled by -1, and
otherwise the return value is the number of files parsed.
This means that the traditional "git_config(...) < 0" check
for error should work, but callers who want to know whether
we parsed any files or not can still do so.

[jc: with tests from Jonathan]

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

1 files changed, 1 insertions, 3 deletions

diff --git a/config.c b/config.c
index 4b0a82040e..c63d6834e0 100644
--- a/config.c
+++ b/config.c
@@ -871,9 +871,7 @@ int git_config(config_fn_t fn, void *data)
 	if (config_parameters)
 		found += 1;
 
-	if (found == 0)
-		return -1;
-	return ret;
+	return ret == 0 ? found : ret;
 }
 
 /*