pass "git -c foo=bar" params through environment

Git uses the "-c foo=bar" parameters to set a config
variable for a single git invocation. We currently do this
by making a list in the current process and consulting that
list in git_config.

This works fine for built-ins, but the config changes are
silently ignored by subprocesses, including dashed externals
and invocations to "git config" from shell scripts.

This patch instead puts them in an environment variable
which we consult when looking at config (both internally and
via calls "git config").

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

1 files changed, 54 insertions, 3 deletions

diff --git a/config.c b/config.c
index cdcf5836c6..c2c995f16d 100644
--- a/config.c
+++ b/config.c
@@ -8,6 +8,7 @@
 #include "cache.h"
 #include "exec_cmd.h"
 #include "strbuf.h"
+#include "quote.h"
 
 #define MAXNAME (256)
 
@@ -34,6 +35,19 @@ static void lowercase(char *p)
 		*p = tolower(*p);
 }
 
+void git_config_push_parameter(const char *text)
+{
+	struct strbuf env = STRBUF_INIT;
+	const char *old = getenv(CONFIG_DATA_ENVIRONMENT);
+	if (old) {
+		strbuf_addstr(&env, old);
+		strbuf_addch(&env, ' ');
+	}
+	sq_quote_buf(&env, text);
+	setenv(CONFIG_DATA_ENVIRONMENT, env.buf, 1);
+	strbuf_release(&env);
+}
+
 int git_config_parse_parameter(const char *text)
 {
 	struct config_item *ct;
@@ -61,6 +75,37 @@ int git_config_parse_parameter(const char *text)
 	return 0;
 }
 
+int git_config_parse_environment(void) {
+	const char *env = getenv(CONFIG_DATA_ENVIRONMENT);
+	char *envw;
+	const char **argv = NULL;
+	int nr = 0, alloc = 0;
+	int i;
+
+	if (!env)
+		return 0;
+	/* sq_dequote will write over it */
+	envw = xstrdup(env);
+
+	if (sq_dequote_to_argv(envw, &argv, &nr, &alloc) < 0) {
+		free(envw);
+		return error("bogus format in " CONFIG_DATA_ENVIRONMENT);
+	}
+
+	for (i = 0; i < nr; i++) {
+		if (git_config_parse_parameter(argv[i]) < 0) {
+			error("bogus config parameter: %s", argv[i]);
+			free(argv);
+			free(envw);
+			return -1;
+		}
+	}
+
+	free(argv);
+	free(envw);
+	return 0;
+}
+
 static int get_next_char(void)
 {
 	int c;
@@ -773,7 +818,14 @@ int git_config_global(void)
 
 int git_config_from_parameters(config_fn_t fn, void *data)
 {
+	static int loaded_environment;
 	const struct config_item *ct;
+
+	if (!loaded_environment) {
+		if (git_config_parse_environment() < 0)
+			return -1;
+		loaded_environment = 1;
+	}
 	for (ct = config_parameters; ct; ct = ct->next)
 		if (fn(ct->name, ct->value, data) < 0)
 			return -1;
@@ -812,10 +864,9 @@ int git_config(config_fn_t fn, void *data)
 	}
 	free(repo_config);
 
-	if (config_parameters) {
-		ret += git_config_from_parameters(fn, data);
+	ret += git_config_from_parameters(fn, data);
+	if (config_parameters)
 		found += 1;
-	}
 
 	if (found == 0)
 		return -1;