[PATCH] builtin-tag.c: remove global variable to use the callback data of git-config.

[Carlos Rica <jasampler@gmail.com>]

By using strbuf to save the signing-key id, now there's no limit
to the length of the string obtained from the config or command-line.
This string is then passed to gpg to sign the tag, when appropriate.

Signed-off-by: Carlos Rica <jasampler@gmail.com>
---


NOTES: As Johannes Schindelin suggested, now strbuf is correctly used,
       using setlen() for chopping the end data of the committer info,
       instead of just setting '\0' and forgetting the len field.

       Although git_committer_info() seems to return always the email
       field between <angle brackets>, I left unchanged the "if (bracket)"
       condition (as in builtin-log.c) to prevent errors or future changes.

       Trying to test it, I found that gpg accepts any non-empty substring
       of the name or email to identify the signing key ID, just as it is
       stated in its manpage at end of section HOW TO SPECIFY A USER ID.


 builtin-tag.c |   41 +++++++++++++++++------------------------
 1 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/builtin-tag.c b/builtin-tag.c
index 01e7374..ad54e4a 100644
--- a/builtin-tag.c
+++ b/builtin-tag.c
@@ -21,8 +21,6 @@ static const char * const git_tag_usage[] = {
 	NULL
 };
 
-static char signingkey[1000];
-
 struct tag_filter {
 	const char *pattern;
 	int lines;
@@ -156,7 +154,7 @@ static int verify_tag(const char *name, const char *ref,
 	return 0;
 }
 
-static int do_sign(struct strbuf *buffer)
+static int do_sign(struct strbuf *signingkey, struct strbuf *buffer)
 {
 	struct child_process gpg;
 	const char *args[4];
@@ -164,13 +162,12 @@ static int do_sign(struct strbuf *buffer)
 	int len;
 	int i, j;
 
-	if (!*signingkey) {
-		if (strlcpy(signingkey, git_committer_info(IDENT_ERROR_ON_NO_NAME),
-				sizeof(signingkey)) > sizeof(signingkey) - 1)
-			return error("committer info too long.");
-		bracket = strchr(signingkey, '>');
+	if (!signingkey->len) {
+		strbuf_addstr(signingkey,
+				git_committer_info(IDENT_ERROR_ON_NO_NAME));
+		bracket = strchr(signingkey->buf, '>');
 		if (bracket)
-			bracket[1] = '\0';
+			strbuf_setlen(signingkey, bracket + 1 - signingkey->buf);
 	}
 
 	/* When the username signingkey is bad, program could be terminated
@@ -183,7 +180,7 @@ static int do_sign(struct strbuf *buffer)
 	gpg.out = -1;
 	args[0] = "gpg";
 	args[1] = "-bsau";
-	args[2] = signingkey;
+	args[2] = signingkey->buf;
 	args[3] = NULL;
 
 	if (start_command(&gpg))
@@ -220,18 +217,12 @@ static const char tag_template[] =
 	"# Write a tag message\n"
 	"#\n";
 
-static void set_signingkey(const char *value)
-{
-	if (strlcpy(signingkey, value, sizeof(signingkey)) >= sizeof(signingkey))
-		die("signing key value too long (%.10s...)", value);
-}
-
 static int git_tag_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "user.signingkey")) {
 		if (!value)
 			return config_error_nonbool(var);
-		set_signingkey(value);
+		strbuf_addstr((struct strbuf *) cb, value);
 		return 0;
 	}
 
@@ -266,9 +257,10 @@ static void write_tag_body(int fd, const unsigned char *sha1)
 	free(buf);
 }
 
-static int build_tag_object(struct strbuf *buf, int sign, unsigned char *result)
+static int build_tag_object(struct strbuf *buf, int sign,
+			struct strbuf *signingkey, unsigned char *result)
 {
-	if (sign && do_sign(buf) < 0)
+	if (sign && do_sign(signingkey, buf) < 0)
 		return error("unable to sign the tag");
 	if (write_sha1_file(buf->buf, buf->len, tag_type, result) < 0)
 		return error("unable to write tag file");
@@ -277,6 +269,7 @@ static int build_tag_object(struct strbuf *buf, int sign, unsigned char *result)
 
 static void create_tag(const unsigned char *object, const char *tag,
 		       struct strbuf *buf, int message, int sign,
+		       struct strbuf *signingkey,
 		       unsigned char *prev, unsigned char *result)
 {
 	enum object_type type;
@@ -331,7 +324,7 @@ static void create_tag(const unsigned char *object, const char *tag,
 
 	strbuf_insert(buf, 0, header_buf, header_len);
 
-	if (build_tag_object(buf, sign, result) < 0) {
+	if (build_tag_object(buf, sign, signingkey, result) < 0) {
 		if (path)
 			fprintf(stderr, "The tag message has been left in %s\n",
 				path);
@@ -363,7 +356,7 @@ static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
 
 int cmd_tag(int argc, const char **argv, const char *prefix)
 {
-	struct strbuf buf = STRBUF_INIT;
+	struct strbuf buf = STRBUF_INIT, signingkey = STRBUF_INIT;
 	unsigned char object[20], prev[20];
 	char ref[PATH_MAX];
 	const char *object_ref, *tag;
@@ -403,14 +396,14 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	git_config(git_tag_config, NULL);
+	git_config(git_tag_config, &signingkey);
 
 	argc = parse_options(argc, argv, options, git_tag_usage, 0);
 	msgfile = parse_options_fix_filename(prefix, msgfile);
 
 	if (keyid) {
 		sign = 1;
-		set_signingkey(keyid);
+		strbuf_addstr(&signingkey, keyid);
 	}
 	if (sign)
 		annotate = 1;
@@ -474,7 +467,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 
 	if (annotate)
 		create_tag(object, tag, &buf, msg.given || msgfile,
-			   sign, prev, object);
+			   sign, &signingkey, prev, object);
 
 	lock = lock_any_ref_for_update(ref, prev, 0);
 	if (!lock)
-- 
1.5.4.3