gpg: centralize printing signature buffers

The code to handle printing of signature data from a struct
signature_check is very similar between verify-commit and verify-tag.
Place this in a single function.  verify-tag retains its special case
behavior of printing the tag even when no valid signature is found.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/verify-commit.c

@@ -26,12 +26,7 @@ static int run_gpg_verify(const unsigned char *sha1, const char *buf, unsigned l
 	memset(&signature_check, 0, sizeof(signature_check));
 
 	ret = check_commit_signature(lookup_commit(sha1), &signature_check);
-
-	if (verbose && signature_check.payload)
-		fputs(signature_check.payload, stdout);
-
-	if (signature_check.gpg_output)
-		fputs(signature_check.gpg_output, stderr);
+	print_signature_buffer(&signature_check, verbose ? GPG_VERIFY_VERBOSE : 0);
 
 	signature_check_clear(&signature_check);
 	return ret;

builtin/verify-tag.c

@@ -27,14 +27,15 @@ static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
 	memset(&sigc, 0, sizeof(sigc));
 
 	len = parse_signature(buf, size);
-	if (verbose)
-		write_in_full(1, buf, len);
 
-	if (size == len)
+	if (size == len) {
+		if (verbose)
+			write_in_full(1, buf, len);
 		return error("no signature found");
+	}
 
 	ret = check_signature(buf, len, buf + len, size - len, &sigc);
-	fputs(sigc.gpg_output, stderr);
+	print_signature_buffer(&sigc, verbose ? GPG_VERIFY_VERBOSE : 0);
 
 	signature_check_clear(&sigc);
 	return ret;

gpg-interface.c

@@ -85,6 +85,15 @@ int check_signature(const char *payload, size_t plen, const char *signature,
 	return sigc->result != 'G' && sigc->result != 'U';
 }
 
+void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
+{
+	if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
+		fputs(sigc->payload, stdout);
+
+	if (sigc->gpg_output)
+		fputs(sigc->gpg_output, stderr);
+}
+
 /*
  * Look at GPG signed content (e.g. a signed tag object), whose
  * payload is followed by a detached signature on it.  Return the

gpg-interface.h

@@ -1,6 +1,8 @@
 #ifndef GPG_INTERFACE_H
 #define GPG_INTERFACE_H
 
+#define GPG_VERIFY_VERBOSE	1
+
 struct signature_check {
 	char *payload;
 	char *gpg_output;
@@ -29,5 +31,6 @@ extern void set_signing_key(const char *);
 extern const char *get_signing_key(void);
 extern int check_signature(const char *payload, size_t plen,
 	const char *signature, size_t slen, struct signature_check *sigc);
+void print_signature_buffer(const struct signature_check *sigc, unsigned flags);
 
 #endif