ident: add user.useConfigOnly boolean for when ident shouldn't be guessed

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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/ident.c b/ident.c
index f796206..4bd8084 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;
 	}