gpg-interface: lazily initialize and read the configuration

Instead of forcing the porcelain commands to always read the
configuration variables related to the signing and verifying
signatures, lazily initialize the necessary subsystem on demand upon
the first use.

This hopefully would make it more future-proof as we do not have to
think and decide whether we should call git_gpg_config() in the
git_config() callback for each command.

A few git_config() callback functions that used to be custom
callbacks are now just a thin wrapper around git_default_config().
We could further remove, git_FOO_config and replace calls to
git_config(git_FOO_config) with git_config(git_default_config), but
to make it clear which ones are affected and the effect is only the
removal of git_gpg_config(), it is vastly preferred not to do such a
change in this step (they can be done on top once the dust settled).

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/gpg-interface.c b/gpg-interface.c
index 687236430b..404d4cccf3 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -9,6 +9,18 @@
 #include "tempfile.h"
 #include "alias.h"
 
+static int git_gpg_config(const char *, const char *, void *);
+
+static void gpg_interface_lazy_init(void)
+{
+	static int done;
+
+	if (done)
+		return;
+	done = 1;
+	git_config(git_gpg_config, NULL);
+}
+
 static char *configured_signing_key;
 static const char *ssh_default_key_command, *ssh_allowed_signers, *ssh_revocation_file;
 static enum signature_trust_level configured_min_trust_level = TRUST_UNDEFINED;
@@ -632,6 +644,8 @@ int check_signature(struct signature_check *sigc,
 	struct gpg_format *fmt;
 	int status;
 
+	gpg_interface_lazy_init();
+
 	sigc->result = 'N';
 	sigc->trust_level = -1;
 
@@ -695,11 +709,13 @@ int parse_signature(const char *buf, size_t size, struct strbuf *payload, struct
 
 void set_signing_key(const char *key)
 {
+	gpg_interface_lazy_init();
+
 	free(configured_signing_key);
 	configured_signing_key = xstrdup(key);
 }
 
-int git_gpg_config(const char *var, const char *value, void *cb UNUSED)
+static int git_gpg_config(const char *var, const char *value, void *cb UNUSED)
 {
 	struct gpg_format *fmt = NULL;
 	char *fmtname = NULL;
@@ -888,6 +904,8 @@ static const char *get_ssh_key_id(void) {
 /* Returns a textual but unique representation of the signing key */
 const char *get_signing_key_id(void)
 {
+	gpg_interface_lazy_init();
+
 	if (use_format->get_key_id) {
 		return use_format->get_key_id();
 	}
@@ -898,6 +916,8 @@ const char *get_signing_key_id(void)
 
 const char *get_signing_key(void)
 {
+	gpg_interface_lazy_init();
+
 	if (configured_signing_key)
 		return configured_signing_key;
 	if (use_format->get_default_key) {
@@ -923,6 +943,8 @@ const char *gpg_trust_level_to_str(enum signature_trust_level level)
 
 int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
 {
+	gpg_interface_lazy_init();
+
 	return use_format->sign_buffer(buffer, signature, signing_key);
 }