Merge branch 'jc/show-sig'

* jc/show-sig:
  log --show-signature: reword the common two-head merge case
  log-tree: show mergetag in log --show-signature output
  log-tree.c: small refactor in show_signature()
  commit --amend -S: strip existing gpgsig headers
  verify_signed_buffer: fix stale comment
  gpg-interface: allow use of a custom GPG binary
  pretty: %G[?GS] placeholders
  test "commit -S" and "log --show-signature"
  log: --show-signature
  commit: teach --gpg-sign option

Conflicts:
	builtin/commit-tree.c
	builtin/commit.c
	builtin/merge.c
	notes-cache.c
	pretty.c

Documentation/RelNotes/1.7.9.txt

@@ -99,10 +99,6 @@ Unless otherwise noted, all the fixes since v1.7.8 in the maintenance
 releases are contained in this release (see release notes to them for
 details).
 
- * gitweb did not correctly fall back to configured $fallback_encoding
-   that is not 'latin1'.
-   (merge b13e3ea jn/maint-gitweb-utf8-fix later to maint).
-
 --
 exec >/var/tmp/1
 O=v1.7.8.2-301-g48de656

Documentation/config.txt

@@ -1123,6 +1123,17 @@ grep.lineNumber::
 grep.extendedRegexp::
 	If set to true, enable '--extended-regexp' option by default.
 
+gpg.program::
+	Use this custom program instead of "gpg" found on $PATH when
+	making or verifying a PGP signature. The program must support the
+	same command line interface as GPG, namely, to verify a detached
+	signature, "gpg --verify $file - <$signature" is run, and the
+	program is expected to signal a good signature by exiting with
+	code 0, and to generate an ascii-armored detached signature, the
+	standard input of "gpg -bsau $key" is fed with the contents to be
+	signed, and the program is expected to send the result to its
+	standard output.
+
 gui.commitmsgwidth::
 	Defines how wide the commit message window is in the
 	linkgit:git-gui[1]. "75" is the default.

Documentation/git-tag.txt

@@ -38,7 +38,9 @@ created (i.e. a lightweight tag).
 A GnuPG signed tag object will be created when `-s` or `-u
 <key-id>` is used.  When `-u <key-id>` is not used, the
 committer identity for the current user is used to find the
-GnuPG key for signing.
+GnuPG key for signing. 	The configuration variable `gpg.program`
+is used to specify custom GnuPG binary.
+
 
 OPTIONS
 -------
@@ -48,11 +50,11 @@ OPTIONS
 
 -s::
 --sign::
-	Make a GPG-signed tag, using the default e-mail address's key
+	Make a GPG-signed tag, using the default e-mail address's key.
 
 -u <key-id>::
 --local-user=<key-id>::
-	Make a GPG-signed tag, using the given key
+	Make a GPG-signed tag, using the given key.
 
 -f::
 --force::

builtin/commit-tree.c

@@ -8,8 +8,9 @@
 #include "tree.h"
 #include "builtin.h"
 #include "utf8.h"
+#include "gpg-interface.h"
 
-static const char commit_tree_usage[] = "git commit-tree [(-p <sha1>)...] [-m <message>] [-F <file>] <sha1> <changelog";
+static const char commit_tree_usage[] = "git commit-tree [(-p <sha1>)...] [-S<signer>] [-m <message>] [-F <file>] <sha1> <changelog";
 
 static void new_parent(struct commit *parent, struct commit_list **parents_p)
 {
@@ -25,19 +26,31 @@ static void new_parent(struct commit *parent, struct commit_list **parents_p)
 	commit_list_insert(parent, parents_p);
 }
 
+static int commit_tree_config(const char *var, const char *value, void *cb)
+{
+	int status = git_gpg_config(var, value, NULL);
+	if (status)
+		return status;
+	return git_default_config(var, value, cb);
+}
+
 int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 {
 	int i, got_tree = 0;
 	struct commit_list *parents = NULL;
 	unsigned char tree_sha1[20];
 	unsigned char commit_sha1[20];
 	struct strbuf buffer = STRBUF_INIT;
+	const char *sign_commit = NULL;
 
-	git_config(git_default_config, NULL);
+	git_config(commit_tree_config, NULL);
 
 	if (argc < 2 || !strcmp(argv[1], "-h"))
 		usage(commit_tree_usage);
 
+	if (get_sha1(argv[1], tree_sha1))
+		die("Not a valid object name %s", argv[1]);
+
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 		if (!strcmp(arg, "-p")) {
@@ -51,6 +64,11 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
+		if (!memcmp(arg, "-S", 2)) {
+			sign_commit = arg + 2;
+			continue;
+		}
+
 		if (!strcmp(arg, "-m")) {
 			if (argc <= ++i)
 				usage(commit_tree_usage);
@@ -98,7 +116,8 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 			die_errno("git commit-tree: failed to read");
 	}
 
-	if (commit_tree(&buffer, tree_sha1, parents, commit_sha1, NULL)) {
+	if (commit_tree(&buffer, tree_sha1, parents, commit_sha1,
+			NULL, sign_commit)) {
 		strbuf_release(&buffer);
 		return 1;
 	}

builtin/commit.c

@@ -26,6 +26,7 @@
 #include "unpack-trees.h"
 #include "quote.h"
 #include "submodule.h"
+#include "gpg-interface.h"
 
 static const char * const builtin_commit_usage[] = {
 	"git commit [options] [--] <filepattern>...",
@@ -86,6 +87,8 @@ static int edit_flag = -1; /* unspecified */
 static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
 static int no_post_rewrite, allow_empty_message;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
+static char *sign_commit;
+
 /*
  * The default commit message cleanup mode will remove the lines
  * beginning with # (shell comments) and leading and trailing
@@ -145,6 +148,8 @@ static struct option builtin_commit_options[] = {
 	OPT_BOOL('e', "edit", &edit_flag, "force edit of commit"),
 	OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
 	OPT_BOOLEAN(0, "status", &include_status, "include status in commit message template"),
+	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
+	  "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	/* end commit message options */
 
 	OPT_GROUP("Commit contents options"),
@@ -1325,6 +1330,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1,
 static int git_commit_config(const char *k, const char *v, void *cb)
 {
 	struct wt_status *s = cb;
+	int status;
 
 	if (!strcmp(k, "commit.template"))
 		return git_config_pathname(&template_file, k, v);
@@ -1333,6 +1339,9 @@ static int git_commit_config(const char *k, const char *v, void *cb)
 		return 0;
 	}
 
+	status = git_gpg_config(k, v, NULL);
+	if (status)
+		return status;
 	return git_status_config(k, v, s);
 }
 
@@ -1486,14 +1495,15 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (amend) {
-		extra = read_commit_extra_headers(current_head);
+		const char *exclude_gpgsig[2] = { "gpgsig", NULL };
+		extra = read_commit_extra_headers(current_head, exclude_gpgsig);
 	} else {
 		struct commit_extra_header **tail = &extra;
 		append_merge_tag_headers(parents, &tail);
 	}
 
 	if (commit_tree_extended(&sb, active_cache_tree->sha1, parents, sha1,
-				 author_ident.buf, extra)) {
+				 author_ident.buf, sign_commit, extra)) {
 		rollback_index_files();
 		die(_("failed to write commit object"));
 	}

builtin/merge.c

@@ -27,6 +27,7 @@
 #include "resolve-undo.h"
 #include "remote.h"
 #include "fmt-merge-msg.h"
+#include "gpg-interface.h"
 
 #define DEFAULT_TWOHEAD (1<<0)
 #define DEFAULT_OCTOPUS (1<<1)
@@ -64,6 +65,7 @@ static int allow_rerere_auto;
 static int abort_current_merge;
 static int show_progress = -1;
 static int default_to_upstream;
+static const char *sign_commit;
 
 static struct strategy all_strategy[] = {
 	{ "recursive",  DEFAULT_TWOHEAD | NO_TRIVIAL },
@@ -209,6 +211,8 @@ static struct option builtin_merge_options[] = {
 	OPT_BOOLEAN(0, "abort", &abort_current_merge,
 		"abort the current in-progress merge"),
 	OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
+	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id",
+	  "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, "update ignored files (default)"),
 	OPT_END()
 };
@@ -571,7 +575,11 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		default_to_upstream = git_config_bool(k, v);
 		return 0;
 	}
+
 	status = fmt_merge_msg_config(k, v, cb);
+	if (status)
+		return status;
+	status = git_gpg_config(k, v, NULL);
 	if (status)
 		return status;
 	return git_diff_ui_config(k, v, cb);
@@ -910,7 +918,8 @@ static int merge_trivial(struct commit *head)
 	parent->next->item = remoteheads->item;
 	parent->next->next = NULL;
 	prepare_to_commit();
-	if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL))
+	if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL,
+			sign_commit))
 		die(_("failed to write commit object"));
 	finish(head, result_commit, "In-index merge");
 	drop_save();
@@ -942,7 +951,8 @@ static int finish_automerge(struct commit *head,
 	strbuf_addch(&merge_msg, '\n');
 	prepare_to_commit();
 	free_commit_list(remoteheads);
-	if (commit_tree(&merge_msg, result_tree, parents, result_commit, NULL))
+	if (commit_tree(&merge_msg, result_tree, parents, result_commit,
+			NULL, sign_commit))
 		die(_("failed to write commit object"));
 	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
 	finish(head, result_commit, buf.buf);