[PATCH 1/4] config: factor out config file stack management

[Heiko Voigt <hvoigt@hvoigt.net>]

Because a config callback may start parsing a new file, the
global context regarding the current config file is stored
as a stack. Currently we only need to manage that stack from
git_config_from_file. Let's factor it out to allow new
sources of config data.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
---

Peff, I hope you do not mind that I totally copied your commit message
here. The patch takes a different approach though. If you like we can
add a

	Commit-Message-by: Jeff King <peff@peff.net>

here :-)

Cheers Heiko

 config.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/config.c b/config.c
index aefd80b..2c299dc 100644
--- a/config.c
+++ b/config.c
@@ -896,6 +896,28 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	return 0;
 }
 
+static int do_config_from(struct config_file *top, config_fn_t fn, void *data)
+{
+	int ret;
+
+	/* push config-file parsing state stack */
+	top->prev = cf;
+	top->linenr = 1;
+	top->eof = 0;
+	strbuf_init(&top->value, 1024);
+	strbuf_init(&top->var, 1024);
+	cf = top;
+
+	ret = git_parse_file(fn, data);
+
+	/* pop config-file parsing state stack */
+	strbuf_release(&top->value);
+	strbuf_release(&top->var);
+	cf = top->prev;
+
+	return ret;
+}
+
 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 {
 	int ret;
@@ -905,22 +927,10 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 	if (f) {
 		config_file top;
 
-		/* push config-file parsing state stack */
-		top.prev = cf;
 		top.f = f;
 		top.name = filename;
-		top.linenr = 1;
-		top.eof = 0;
-		strbuf_init(&top.value, 1024);
-		strbuf_init(&top.var, 1024);
-		cf = &top;
-
-		ret = git_parse_file(fn, data);
-
-		/* pop config-file parsing state stack */
-		strbuf_release(&top.value);
-		strbuf_release(&top.var);
-		cf = top.prev;
+
+		ret = do_config_from(&top, fn, data);
 
 		fclose(f);
 	}
-- 
1.8.2.rc0.26.gf7384c5