credential: handle `credential.<partial-URL>.<key>` again

In the patches for CVE-2020-11008, the ability to specify credential
settings in the config for partial URLs got lost. For example, it used
to be possible to specify a credential helper for a specific protocol:

	[credential "https://"]
		helper = my-https-helper

Likewise, it used to be possible to configure settings for a specific
host, e.g.:

	[credential "dev.azure.com"]
		useHTTPPath = true

Let's reinstate this behavior.

While at it, increase the test coverage to document and verify the
behavior with a couple other categories of partial URLs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/urlmatch.c b/urlmatch.c
index 29272a5..33a2ccd 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -572,10 +572,14 @@ int urlmatch_config_entry(const char *var, const char *value, void *cb)
 
 		config_url = xmemdupz(key, dot - key);
 		norm_url = url_normalize_1(config_url, &norm_info, 1);
+		if (norm_url)
+			retval = match_urls(url, &norm_info, &matched);
+		else if (collect->fallback_match_fn)
+			retval = collect->fallback_match_fn(config_url,
+							    collect->cb);
+		else
+			retval = 0;
 		free(config_url);
-		if (!norm_url)
-			return 0;
-		retval = match_urls(url, &norm_info, &matched);
 		free(norm_url);
 		if (!retval)
 			return 0;