[PATCH] git format-patch --signature <string | file>

[Jeremiah Mahler <jmmahler@gmail.com>]

Improved format-patch --signature option so that it can
read from a file as well as from a string.

  # from a string
  $ git format-patch --signature "from a string" origin

  # or from a file
  $ git format-patch --signature ~/.signature origin

Now signatures with newlines or other special characters
can be easily included.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
---
 builtin/log.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/builtin/log.c b/builtin/log.c
index 39e8836..5988f8f 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1147,6 +1147,27 @@ static int from_callback(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+static int signature_callback(const struct option *opt, const char *arg,
+							int unset)
+{
+	const char **signature = opt->value;
+	static char buf[1024];
+	size_t sz;
+	FILE *fp;
+
+	fp = fopen(arg, "r");
+	if (fp) {
+		sz = sizeof(buf);
+		sz = fread(buf, 1, sz - 1, fp);
+		buf[sz] = '\0';
+		*signature = buf;
+		fclose(fp);
+	} else {
+		*signature = arg;
+	}
+	return 0;
+}
+
 int cmd_format_patch(int argc, const char **argv, const char *prefix)
 {
 	struct commit *commit;
@@ -1228,8 +1249,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		{ OPTION_CALLBACK, 0, "thread", &thread, N_("style"),
 			    N_("enable message threading, styles: shallow, deep"),
 			    PARSE_OPT_OPTARG, thread_callback },
-		OPT_STRING(0, "signature", &signature, N_("signature"),
-			    N_("add a signature")),
+		{ OPTION_CALLBACK, 0, "signature", &signature, N_("signature-file"),
+				N_("add a signature from a string or a file"),
+			    PARSE_OPT_NONEG, signature_callback },
 		OPT__QUIET(&quiet, N_("don't print the patch filenames")),
 		OPT_END()
 	};
-- 
Jeremiah Mahler
jmmahler@gmail.com
http://github.com/jmahler