[PATCH v9] ident: add user.useConfigOnly boolean for when ident shouldn't be guessed

[PATCH v9] ident: add user.useConfigOnly boolean for when ident shouldn't be guessed

[Dan Aloni]

Changes between v8 -> v9:

* Rebased and tested on v2.7.1.
* Made a small correction suggested by Junio in the documentation for
  the new option: s/upon/before

v8: http://article.gmane.org/gmane.comp.version-control.git/285646

[PATCH v9 1/2] fmt_ident: refactor strictness checks

[Dan Aloni]

From: Jeff King <peff@peff.net>

This function has evolved quite a bit over time, and as a
result, the logic for "is this an OK ident" has been
sprinkled throughout. This ends up with a lot of redundant
conditionals, like checking want_name repeatedly. Worse,
we want to know in many cases whether we are using the
"default" ident, and we do so by comparing directly to the
global strbuf, which violates the abstraction of the
ident_default_* functions.

Let's reorganize the function into a hierarchy of
conditionals to handle similar cases together. The only
case that doesn't just work naturally for this is that of an
empty name, where our advice is different based on whether
we came from ident_default_name() or not. We can use a
simple flag to cover this case.

Signed-off-by: Jeff King <peff@peff.net>
---
 ident.c | 46 ++++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/ident.c b/ident.c
index 3da555634290..f3a431f738cc 100644
--- a/ident.c
+++ b/ident.c
@@ -345,32 +345,34 @@ const char *fmt_ident(const char *name, const char *email,
 	int want_date = !(flag & IDENT_NO_DATE);
 	int want_name = !(flag & IDENT_NO_NAME);
 
-	if (want_name && !name)
-		name = ident_default_name();
-	if (!email)
-		email = ident_default_email();
-
-	if (want_name && !*name) {
-		struct passwd *pw;
-
-		if (strict) {
-			if (name == git_default_name.buf)
+	if (want_name) {
+		int using_default = 0;
+		if (!name) {
+			name = ident_default_name();
+			using_default = 1;
+			if (strict && default_name_is_bogus) {
 				fputs(env_hint, stderr);
-			die("empty ident name (for <%s>) not allowed", email);
+				die("unable to auto-detect name (got '%s')", name);
+			}
+		}
+		if (!*name) {
+			struct passwd *pw;
+			if (strict) {
+				if (using_default)
+					fputs(env_hint, stderr);
+				die("empty ident name (for <%s>) not allowed", email);
+			}
+			pw = xgetpwuid_self(NULL);
+			name = pw->pw_name;
 		}
-		pw = xgetpwuid_self(NULL);
-		name = pw->pw_name;
-	}
-
-	if (want_name && strict &&
-	    name == git_default_name.buf && default_name_is_bogus) {
-		fputs(env_hint, stderr);
-		die("unable to auto-detect name (got '%s')", name);
 	}
 
-	if (strict && email == git_default_email.buf && default_email_is_bogus) {
-		fputs(env_hint, stderr);
-		die("unable to auto-detect email address (got '%s')", email);
+	if (!email) {
+		email = ident_default_email();
+		if (strict && default_email_is_bogus) {
+			fputs(env_hint, stderr);
+			die("unable to auto-detect email address (got '%s')", email);
+		}
 	}
 
 	strbuf_reset(&ident);
-- 
2.5.0

[PATCH v9 2/2] ident: add user.useConfigOnly boolean for when ident shouldn't be guessed

[Dan Aloni]

It used to be that:

   git config --global user.email "(none)"

was a viable way for people to force themselves to set user.email in
each repository.  This was helpful for people with more than one
email address, targeting different email addresses for different
clones, as it barred git from creating a commit unless the user.email
config was set in the per-repo config to the correct email address.

A recent change, 19ce497c (ident: keep a flag for bogus
default_email, 2015-12-10), however, declared that an explicitly
configured user.email is not bogus, no matter what its value is, so
this hack no longer works.

Provide the same functionality by adding a new configuration
variable user.useConfigOnly; when this variable is set, the
user must explicitly set user.email configuration.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Dan Aloni <alonid@gmail.com>
---
 Documentation/config.txt  | 10 ++++++++++
 ident.c                   | 16 ++++++++++++++++
 t/t7517-per-repo-email.sh | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100755 t/t7517-per-repo-email.sh

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 02bcde6bb596..cfb7d0e7652d 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2821,6 +2821,16 @@ user.name::
 	Can be overridden by the 'GIT_AUTHOR_NAME' and 'GIT_COMMITTER_NAME'
 	environment variables.  See linkgit:git-commit-tree[1].
 
+user.useConfigOnly::
+	Instruct Git to avoid trying to guess defaults for 'user.email'
+	and 'user.name', and instead retrieve the values only from the
+	configuration. For example, if you have multiple email addresses
+	and would like to use a different one for each repository, then
+	with this configuration option set to `true` in the global config
+	along with a name, Git will prompt you to set up an email before
+	making new commits in a newly cloned repository.
+	Defaults to `false`.
+
 user.signingKey::
 	If linkgit:git-tag[1] or linkgit:git-commit[1] is not selecting the
 	key you want it to automatically when creating a signed tag or
diff --git a/ident.c b/ident.c
index f3a431f738cc..6e125821f056 100644
--- a/ident.c
+++ b/ident.c
@@ -13,11 +13,14 @@ static struct strbuf git_default_date = STRBUF_INIT;
 static int default_email_is_bogus;
 static int default_name_is_bogus;
 
+static int ident_use_config_only;
+
 #define IDENT_NAME_GIVEN 01
 #define IDENT_MAIL_GIVEN 02
 #define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
 static int committer_ident_explicitly_given;
 static int author_ident_explicitly_given;
+static int ident_config_given;
 
 #ifdef NO_GECOS_IN_PWENT
 #define get_gecos(ignored) "&"
@@ -354,6 +357,9 @@ const char *fmt_ident(const char *name, const char *email,
 				fputs(env_hint, stderr);
 				die("unable to auto-detect name (got '%s')", name);
 			}
+			if (strict && ident_use_config_only
+			    && !(ident_config_given & IDENT_NAME_GIVEN))
+				die("user.useConfigOnly set but no name given");
 		}
 		if (!*name) {
 			struct passwd *pw;
@@ -373,6 +379,9 @@ const char *fmt_ident(const char *name, const char *email,
 			fputs(env_hint, stderr);
 			die("unable to auto-detect email address (got '%s')", email);
 		}
+		if (strict && ident_use_config_only
+		    && !(ident_config_given & IDENT_MAIL_GIVEN))
+			die("user.useConfigOnly set but no mail given");
 	}
 
 	strbuf_reset(&ident);
@@ -446,6 +455,11 @@ int author_ident_sufficiently_given(void)
 
 int git_ident_config(const char *var, const char *value, void *data)
 {
+	if (!strcmp(var, "user.useconfigonly")) {
+		ident_use_config_only = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "user.name")) {
 		if (!value)
 			return config_error_nonbool(var);
@@ -453,6 +467,7 @@ int git_ident_config(const char *var, const char *value, void *data)
 		strbuf_addstr(&git_default_name, value);
 		committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 		author_ident_explicitly_given |= IDENT_NAME_GIVEN;
+		ident_config_given |= IDENT_NAME_GIVEN;
 		return 0;
 	}
 
@@ -463,6 +478,7 @@ int git_ident_config(const char *var, const char *value, void *data)
 		strbuf_addstr(&git_default_email, value);
 		committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 		author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
+		ident_config_given |= IDENT_MAIL_GIVEN;
 		return 0;
 	}
 
diff --git a/t/t7517-per-repo-email.sh b/t/t7517-per-repo-email.sh
new file mode 100755
index 000000000000..337e6e30c35f
--- /dev/null
+++ b/t/t7517-per-repo-email.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+#
+# Copyright (c) 2016 Dan Aloni
+# Copyright (c) 2016 Jeff King
+#
+
+test_description='per-repo forced setting of email address'
+
+. ./test-lib.sh
+
+test_expect_success 'setup a likely user.useConfigOnly use case' '
+	# we want to make sure a reflog is written, since that needs
+	# a non-strict ident. So be sure we have an actual commit.
+	test_commit foo &&
+
+	sane_unset GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL &&
+	sane_unset GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL &&
+	git config user.name "test" &&
+	git config --global user.useConfigOnly true
+'
+
+test_expect_success 'fails committing if clone email is not set' '
+	test_must_fail git commit --allow-empty -m msg
+'
+
+test_expect_success 'fails committing if clone email is not set, but EMAIL set' '
+	test_must_fail env EMAIL=test@fail.com git commit --allow-empty -m msg
+'
+
+test_expect_success 'succeeds committing if clone email is set' '
+	test_config user.email "test@ok.com" &&
+	git commit --allow-empty -m msg
+'
+
+test_expect_success 'succeeds cloning if global email is not set' '
+	git clone . clone
+'
+
+test_done
-- 
2.5.0

Re: [PATCH v9] ident: add user.useConfigOnly boolean for when ident shouldn't be guessed

[Junio C Hamano]

Thanks.