Merge branch 'nv/commit-gpgsign-config'

Introduce commit.gpgsign configuration variable to force every
commit to be GPG signed.  The variable cannot be overriden from the
command line of some of the commands that create commits except for
"git commit" and "git commit-tree", but I am not convinced that it
is a good idea to sprinkle support for --no-gpg-sign everywhere,
which in turn means that this configuration variable may not be
such a good idea.

* nv/commit-gpgsign-config:
  test the commit.gpgsign config option
  commit-tree: add and document --no-gpg-sign
  commit-tree: add the commit.gpgsign option to sign all commits

Documentation/config.txt

@@ -992,6 +992,14 @@ commit.cleanup::
 	have to remove the help lines that begin with `#` in the commit log
 	template yourself, if you do this).
 
+commit.gpgsign::
+
+	A boolean to specify whether all commits should be GPG signed.
+	Use of this option when doing operations such as rebase can
+	result in a large number of commits being signed. It may be
+	convenient to use an agent to avoid typing your GPG passphrase
+	several times.
+
 commit.status::
 	A boolean to enable/disable inclusion of status information in the
 	commit message template when using an editor to prepare the commit

Documentation/git-commit-tree.txt

@@ -55,8 +55,13 @@ OPTIONS
 	from the standard input.
 
 -S[<keyid>]::
+--gpg-sign[=<keyid>]::
 	GPG-sign commit.
 
+--no-gpg-sign::
+	Countermand `commit.gpgsign` configuration variable that is
+	set to force each and every commit to be signed.
+
 
 Commit Information
 ------------------

Documentation/git-commit.txt

@@ -302,6 +302,10 @@ configuration variable documented in linkgit:git-config[1].
 --gpg-sign[=<keyid>]::
 	GPG-sign commit.
 
+--no-gpg-sign::
+	Countermand `commit.gpgsign` configuration variable that is
+	set to force each and every commit to be signed.
+
 \--::
 	Do not interpret any more arguments as options.
 

builtin/commit-tree.c

@@ -12,6 +12,8 @@
 
 static const char commit_tree_usage[] = "git commit-tree [(-p <sha1>)...] [-S[<keyid>]] [-m <message>] [-F <file>] <sha1> <changelog";
 
+static const char *sign_commit;
+
 static void new_parent(struct commit *parent, struct commit_list **parents_p)
 {
 	unsigned char *sha1 = parent->object.sha1;
@@ -31,6 +33,10 @@ 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;
+	if (!strcmp(var, "commit.gpgsign")) {
+		sign_commit = git_config_bool(var, value) ? "" : NULL;
+		return 0;
+	}
 	return git_default_config(var, value, cb);
 }
 
@@ -41,7 +47,6 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 	unsigned char tree_sha1[20];
 	unsigned char commit_sha1[20];
 	struct strbuf buffer = STRBUF_INIT;
-	const char *sign_commit = NULL;
 
 	git_config(commit_tree_config, NULL);
 
@@ -66,6 +71,11 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
+		if (!strcmp(arg, "--no-gpg-sign")) {
+			sign_commit = NULL;
+			continue;
+		}
+
 		if (!strcmp(arg, "-m")) {
 			if (argc <= ++i)
 				usage(commit_tree_usage);

builtin/commit.c

@@ -1406,6 +1406,10 @@ static int git_commit_config(const char *k, const char *v, void *cb)
 	}
 	if (!strcmp(k, "commit.cleanup"))
 		return git_config_string(&cleanup_arg, k, v);
+	if (!strcmp(k, "commit.gpgsign")) {
+		sign_commit = git_config_bool(k, v) ? "" : NULL;
+		return 0;
+	}
 
 	status = git_gpg_config(k, v, NULL);
 	if (status)

builtin/merge.c

@@ -597,6 +597,9 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 	} else if (!strcmp(k, "merge.defaulttoupstream")) {
 		default_to_upstream = git_config_bool(k, v);
 		return 0;
+	} else if (!strcmp(k, "commit.gpgsign")) {
+		sign_commit = git_config_bool(k, v) ? "" : NULL;
+		return 0;
 	}
 
 	status = fmt_merge_msg_config(k, v, cb);

t/t7510-signed-commit.sh

@@ -5,6 +5,8 @@ test_description='signed commit tests'
 . "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success GPG 'create signed commits' '
+	test_when_finished "test_unconfig commit.gpgsign" &&
+
 	echo 1 >file && git add file &&
 	test_tick && git commit -S -m initial &&
 	git tag initial &&
@@ -25,12 +27,27 @@ test_expect_success GPG 'create signed commits' '
 	git tag fourth-unsigned &&
 
 	test_tick && git commit --amend -S -m "fourth signed" &&
-	git tag fourth-signed
+	git tag fourth-signed &&
+
+	git config commit.gpgsign true &&
+	echo 5 >file && test_tick && git commit -a -m "fifth signed" &&
+	git tag fifth-signed &&
+
+	git config commit.gpgsign false &&
+	echo 6 >file && test_tick && git commit -a -m "sixth" &&
+	git tag sixth-unsigned &&
+
+	git config commit.gpgsign true &&
+	echo 7 >file && test_tick && git commit -a -m "seventh" --no-gpg-sign &&
+	git tag seventh-unsigned &&
+
+	test_tick && git rebase -f HEAD^^ && git tag sixth-signed HEAD^ &&
+	git tag seventh-signed
 '
 
 test_expect_success GPG 'show signatures' '
 	(
-		for commit in initial second merge master
+		for commit in initial second merge fourth-signed fifth-signed sixth-signed master
 		do
 			git show --pretty=short --show-signature $commit >actual &&
 			grep "Good signature from" actual || exit 1
@@ -39,7 +56,7 @@ test_expect_success GPG 'show signatures' '
 		done
 	) &&
 	(
-		for commit in merge^2 fourth-unsigned
+		for commit in merge^2 fourth-unsigned sixth-unsigned seventh-unsigned
 		do
 			git show --pretty=short --show-signature $commit >actual &&
 			grep "Good signature from" actual && exit 1
@@ -52,7 +69,7 @@ test_expect_success GPG 'show signatures' '
 test_expect_success GPG 'detect fudged signature' '
 	git cat-file commit master >raw &&
 
-	sed -e "s/fourth signed/4th forged/" raw >forged1 &&
+	sed -e "s/seventh/7th forged/" raw >forged1 &&
 	git hash-object -w -t commit forged1 >forged1.commit &&
 	git show --pretty=short --show-signature $(cat forged1.commit) >actual1 &&
 	grep "BAD signature from" actual1 &&