git credential fill: output the whole 'struct credential'

Instead of outputing only the username and password, print all the
attributes, even those that already appeared in the input.

This is closer to what the C API does, and allows one to take the exact
output of "git credential fill" as input to "git credential approve" or
"git credential reject".

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

Documentation/git-credential.txt

@@ -64,12 +64,20 @@ infomation it has):
 
   2. Ask git-credential to give us a username and password for this
      description. This is done by running `git credential fill`,
-     feeding the description from step (1) to its standard input. The
-     credential will be produced on standard output, like:
+     feeding the description from step (1) to its standard input. The complete
+     credential description (including the credential per se, i.e. the
+     login and password) will be produced on standard output, like:
 
+	protocol=https
+	host=example.com
 	username=bob
 	password=secr3t
 +
+In most cases, this means the attributes given in the input will be
+repeated in the output, but git may also modify the credential
+description, for example by removing the `path` attribute when the
+protocol is HTTP(s) and `credential.useHttpPath` is false.
++
 If the `git credential` knew about the password, this step may
 not have involved the user actually typing this password (the
 user may have typed a password to unlock the keychain instead,
@@ -86,8 +94,8 @@ unlocked) before it returned `password=secr3t`.
      was rejected during the operation, use the "reject" action so
      that `git credential` will ask for a new password in its next
      invocation. In either case, `git credential` should be fed with
-     the credential description obtained from step (2) together with
-     the ones already provided in step (1).
+     the credential description obtained from step (2) (which also
+     contain the ones provided in step (1)).
 
 [[IOFMT]]
 INPUT/OUTPUT FORMAT

builtin/credential.c

@@ -19,10 +19,7 @@ int cmd_credential(int argc, const char **argv, const char *prefix)
 
 	if (!strcmp(op, "fill")) {
 		credential_fill(&c);
-		if (c.username)
-			printf("username=%s\n", c.username);
-		if (c.password)
-			printf("password=%s\n", c.password);
+		credential_write(&c, stdout);
 	} else if (!strcmp(op, "approve")) {
 		credential_approve(&c);
 	} else if (!strcmp(op, "reject")) {

credential.c

@@ -191,7 +191,7 @@ static void credential_write_item(FILE *fp, const char *key, const char *value)
 	fprintf(fp, "%s=%s\n", key, value);
 }
 
-static void credential_write(const struct credential *c, FILE *fp)
+void credential_write(const struct credential *c, FILE *fp)
 {
 	credential_write_item(fp, "protocol", c->protocol);
 	credential_write_item(fp, "host", c->host);

credential.h

@@ -26,6 +26,7 @@ void credential_approve(struct credential *);
 void credential_reject(struct credential *);
 
 int credential_read(struct credential *, FILE *);
+void credential_write(const struct credential *, FILE *);
 void credential_from_url(struct credential *, const char *url);
 int credential_match(const struct credential *have,
 		     const struct credential *want);

t/lib-credential.sh

@@ -62,6 +62,8 @@ helper_test() {
 		protocol=https
 		host=example.com
 		--
+		protocol=https
+		host=example.com
 		username=askpass-username
 		password=askpass-password
 		--
@@ -84,6 +86,8 @@ helper_test() {
 		protocol=https
 		host=example.com
 		--
+		protocol=https
+		host=example.com
 		username=store-user
 		password=store-pass
 		--
@@ -95,6 +99,8 @@ helper_test() {
 		protocol=http
 		host=example.com
 		--
+		protocol=http
+		host=example.com
 		username=askpass-username
 		password=askpass-password
 		--
@@ -108,6 +114,8 @@ helper_test() {
 		protocol=https
 		host=other.tld
 		--
+		protocol=https
+		host=other.tld
 		username=askpass-username
 		password=askpass-password
 		--
@@ -122,6 +130,8 @@ helper_test() {
 		host=example.com
 		username=other
 		--
+		protocol=https
+		host=example.com
 		username=other
 		password=askpass-password
 		--
@@ -143,6 +153,9 @@ helper_test() {
 		host=path.tld
 		path=bar.git
 		--
+		protocol=http
+		host=path.tld
+		path=bar.git
 		username=askpass-username
 		password=askpass-password
 		--
@@ -160,6 +173,8 @@ helper_test() {
 		protocol=https
 		host=example.com
 		--
+		protocol=https
+		host=example.com
 		username=askpass-username
 		password=askpass-password
 		--
@@ -186,6 +201,8 @@ helper_test() {
 		host=example.com
 		username=user1
 		--
+		protocol=https
+		host=example.com
 		username=user1
 		password=pass1
 		EOF
@@ -194,6 +211,8 @@ helper_test() {
 		host=example.com
 		username=user2
 		--
+		protocol=https
+		host=example.com
 		username=user2
 		password=pass2
 		EOF
@@ -210,6 +229,8 @@ helper_test() {
 		host=example.com
 		username=user1
 		--
+		protocol=https
+		host=example.com
 		username=user1
 		password=askpass-password
 		--
@@ -223,6 +244,8 @@ helper_test() {
 		host=example.com
 		username=user2
 		--
+		protocol=https
+		host=example.com
 		username=user2
 		password=pass2
 		EOF
@@ -244,6 +267,8 @@ helper_test_timeout() {
 		protocol=https
 		host=timeout.tld
 		--
+		protocol=https
+		host=timeout.tld
 		username=askpass-username
 		password=askpass-password
 		--

t/t0300-credentials.sh

@@ -82,6 +82,9 @@ test_expect_success 'credential_fill passes along metadata' '
 	host=example.com
 	path=foo.git
 	--
+	protocol=ftp
+	host=example.com
+	path=foo.git
 	username=one
 	password=two
 	--
@@ -213,6 +216,8 @@ test_expect_success 'match configured credential' '
 	host=example.com
 	path=repo.git
 	--
+	protocol=https
+	host=example.com
 	username=foo
 	password=bar
 	--
@@ -225,6 +230,8 @@ test_expect_success 'do not match configured credential' '
 	protocol=https
 	host=bar
 	--
+	protocol=https
+	host=bar
 	username=askpass-username
 	password=askpass-password
 	--
@@ -239,6 +246,8 @@ test_expect_success 'pull username from config' '
 	protocol=https
 	host=example.com
 	--
+	protocol=https
+	host=example.com
 	username=foo
 	password=askpass-password
 	--
@@ -252,6 +261,8 @@ test_expect_success 'http paths can be part of context' '
 	host=example.com
 	path=foo.git
 	--
+	protocol=https
+	host=example.com
 	username=foo
 	password=bar
 	--
@@ -265,6 +276,9 @@ test_expect_success 'http paths can be part of context' '
 	host=example.com
 	path=foo.git
 	--
+	protocol=https
+	host=example.com
+	path=foo.git
 	username=foo
 	password=bar
 	--