[PATCH 3/5] Expose verify_tag()

[Jonathan Nieder <jrnieder@gmail.com>]

Expose the verify_tag() function so ‘git tag -v’ can use it directly
in the future.  verify_tag() already frees all the memory it allocates
and does not call any functions that can exit, so this should be safe.

The function is renamed to verify_tag_signature() for clarity and to
avoid conflicting with builtin/tag.c and builtin/mktag.c’s unrelated
verify_tag().

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile                             |    1 +
 builtin/verify-tag.c                 |   85 +---------------------------------
 tag.h                                |    1 +
 builtin/verify-tag.c => verify-tag.c |   34 +-------------
 4 files changed, 4 insertions(+), 117 deletions(-)
 copy builtin/verify-tag.c => verify-tag.c (71%)

diff --git a/Makefile b/Makefile
index 7c616f8..ed58261 100644
--- a/Makefile
+++ b/Makefile
@@ -616,6 +616,7 @@ LIB_OBJS += unpack-trees.o
 LIB_OBJS += usage.o
 LIB_OBJS += userdiff.o
 LIB_OBJS += utf8.o
+LIB_OBJS += verify-tag.o
 LIB_OBJS += walker.o
 LIB_OBJS += wrapper.o
 LIB_OBJS += write_or_die.o
diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c
index 91dd1c1..ca075bd 100644
--- a/builtin/verify-tag.c
+++ b/builtin/verify-tag.c
@@ -5,12 +5,8 @@
  *
  * Based on git-verify-tag.sh
  */
-#include "cache.h"
 #include "builtin.h"
 #include "tag.h"
-#include "run-command.h"
-#include <signal.h>
-#include "sigchain.h"
 #include "parse-options.h"
 
 static const char * const verify_tag_usage[] = {
@@ -18,85 +14,6 @@ static const char * const verify_tag_usage[] = {
 		NULL
 };
 
-#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
-
-static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
-{
-	struct child_process gpg;
-	const char *args_gpg[] = {"gpg", "--verify", "FILE", "-", NULL};
-	char path[PATH_MAX], *eol;
-	size_t len;
-	int fd, ret;
-
-	fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
-	if (fd < 0)
-		return error("could not create temporary file '%s': %s",
-						path, strerror(errno));
-	if (write_in_full(fd, buf, size) < 0)
-		return error("failed writing temporary file '%s': %s",
-						path, strerror(errno));
-	close(fd);
-
-	/* find the length without signature */
-	len = 0;
-	while (len < size && prefixcmp(buf + len, PGP_SIGNATURE)) {
-		eol = memchr(buf + len, '\n', size - len);
-		len += eol ? eol - (buf + len) + 1 : size - len;
-	}
-	if (verbose)
-		write_in_full(1, buf, len);
-
-	memset(&gpg, 0, sizeof(gpg));
-	gpg.argv = args_gpg;
-	gpg.in = -1;
-	args_gpg[2] = path;
-	if (start_command(&gpg)) {
-		unlink(path);
-		return error("could not run gpg.");
-	}
-
-	/*
-	 * gpg will stop as soon as it knows the signature is bad,
-	 * which can result in SIGPIPE.
-	 */
-	sigchain_push(SIGPIPE, SIG_IGN);
-	write_in_full(gpg.in, buf, len);
-	close(gpg.in);
-	sigchain_pop(SIGPIPE);
-
-	ret = finish_command(&gpg);
-
-	unlink_or_warn(path);
-
-	return ret;
-}
-
-static int verify_tag(const char *name, int verbose)
-{
-	enum object_type type;
-	unsigned char sha1[20];
-	char *buf;
-	unsigned long size;
-	int ret;
-
-	if (get_sha1(name, sha1))
-		return error("tag '%s' not found.", name);
-
-	type = sha1_object_info(sha1, NULL);
-	if (type != OBJ_TAG)
-		return error("%s: cannot verify a non-tag object of type %s.",
-				name, typename(type));
-
-	buf = read_sha1_file(sha1, &type, &size);
-	if (!buf)
-		return error("%s: unable to read file.", name);
-
-	ret = run_gpg_verify(buf, size, verbose);
-
-	free(buf);
-	return ret;
-}
-
 int cmd_verify_tag(int argc, const char **argv, const char *prefix)
 {
 	int i = 1, verbose = 0, had_error = 0;
@@ -113,7 +30,7 @@ int cmd_verify_tag(int argc, const char **argv, const char *prefix)
 		usage_with_options(verify_tag_usage, verify_tag_options);
 
 	while (i < argc)
-		if (verify_tag(argv[i++], verbose))
+		if (verify_tag_signature(argv[i++], verbose))
 			had_error = 1;
 	return had_error;
 }
diff --git a/tag.h b/tag.h
index 7a0cb00..1034109 100644
--- a/tag.h
+++ b/tag.h
@@ -16,5 +16,6 @@ extern struct tag *lookup_tag(const unsigned char *sha1);
 extern int parse_tag_buffer(struct tag *item, void *data, unsigned long size);
 extern int parse_tag(struct tag *item);
 extern struct object *deref_tag(struct object *, const char *, int);
+extern int verify_tag_signature(const char *name, int verbose);
 
 #endif /* TAG_H */
diff --git a/builtin/verify-tag.c b/verify-tag.c
similarity index 71%
copy from builtin/verify-tag.c
copy to verify-tag.c
index 91dd1c1..7152e99 100644
--- a/builtin/verify-tag.c
+++ b/verify-tag.c
@@ -1,22 +1,11 @@
 /*
- * Builtin "git verify-tag"
- *
  * Copyright (c) 2007 Carlos Rica <jasampler@gmail.com>
- *
- * Based on git-verify-tag.sh
  */
 #include "cache.h"
-#include "builtin.h"
 #include "tag.h"
 #include "run-command.h"
 #include <signal.h>
 #include "sigchain.h"
-#include "parse-options.h"
-
-static const char * const verify_tag_usage[] = {
-		"git verify-tag [-v|--verbose] <tag>...",
-		NULL
-};
 
 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
 
@@ -71,7 +60,7 @@ static int run_gpg_verify(const char *buf, unsigned long size, int verbose)
 	return ret;
 }
 
-static int verify_tag(const char *name, int verbose)
+int verify_tag_signature(const char *name, int verbose)
 {
 	enum object_type type;
 	unsigned char sha1[20];
@@ -96,24 +85,3 @@ static int verify_tag(const char *name, int verbose)
 	free(buf);
 	return ret;
 }
-
-int cmd_verify_tag(int argc, const char **argv, const char *prefix)
-{
-	int i = 1, verbose = 0, had_error = 0;
-	const struct option verify_tag_options[] = {
-		OPT__VERBOSE(&verbose),
-		OPT_END()
-	};
-
-	git_config(git_default_config, NULL);
-
-	argc = parse_options(argc, argv, prefix, verify_tag_options,
-			     verify_tag_usage, PARSE_OPT_KEEP_ARGV0);
-	if (argc <= i)
-		usage_with_options(verify_tag_usage, verify_tag_options);
-
-	while (i < argc)
-		if (verify_tag(argv[i++], verbose))
-			had_error = 1;
-	return had_error;
-}
-- 
1.7.0.2