Merge branch 'sf/putty-w-args'

The command line options for ssh invocation needs to be tweaked for
some implementations of SSH (e.g. PuTTY plink wants "-P <port>"
while OpenSSH wants "-p <port>" to specify port to connect to), and
the variant was guessed when GIT_SSH environment variable is used
to specify it.  The logic to guess now applies to the command
specified by the newer GIT_SSH_COMMAND and also core.sshcommand
configuration variable, and comes with an escape hatch for users to
deal with misdetected cases.

* sf/putty-w-args:
  connect.c: stop conflating ssh command names and overrides
  connect: Add the envvar GIT_SSH_VARIANT and ssh.variant config
  git_connect(): factor out SSH variant handling
  connect: rename tortoiseplink and putty variables
  connect: handle putty/plink also in GIT_SSH_COMMAND

4 files changed, 133 insertions, 19 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 10351a2100..9dbd96dbba 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1957,6 +1957,17 @@ Environment variable settings always override any matches.  The URLs that are
 matched against are those given directly to Git commands.  This means any URLs
 visited as a result of a redirection do not participate in matching.
 
+ssh.variant::
+	Depending on the value of the environment variables `GIT_SSH` or
+	`GIT_SSH_COMMAND`, or the config setting `core.sshCommand`, Git
+	auto-detects whether to adjust its command-line parameters for use
+	with plink or tortoiseplink, as opposed to the default (OpenSSH).
++
+The config variable `ssh.variant` can be set to override this auto-detection;
+valid values are `ssh`, `plink`, `putty` or `tortoiseplink`. Any other value
+will be treated as normal ssh. This setting can be overridden via the
+environment variable `GIT_SSH_VARIANT`.
+
 i18n.commitEncoding::
 	Character encoding the commit messages are stored in; Git itself
 	does not care per se, but this information is necessary e.g. when
diff --git a/Documentation/git.txt b/Documentation/git.txt
index aa895da4a5..df0941d456 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1025,6 +1025,12 @@ Usually it is easier to configure any desired options through your
 personal `.ssh/config` file.  Please consult your ssh documentation
 for further details.
 
+`GIT_SSH_VARIANT`::
+	If this environment variable is set, it overrides Git's autodetection
+	whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH,
+	plink or tortoiseplink. This variable overrides the config setting
+	`ssh.variant` that serves the same purpose.
+
 `GIT_ASKPASS`::
 	If this environment variable is set, then Git commands which need to
 	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
diff --git a/connect.c b/connect.c
index 8cb93b0720..7d65c1c736 100644
--- a/connect.c
+++ b/connect.c
@@ -691,6 +691,68 @@ static const char *get_ssh_command(void)
 	return NULL;
 }
 
+static int override_ssh_variant(int *port_option, int *needs_batch)
+{
+	char *variant;
+
+	variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
+	if (!variant &&
+	    git_config_get_string("ssh.variant", &variant))
+		return 0;
+
+	if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
+		*port_option = 'P';
+		*needs_batch = 0;
+	} else if (!strcmp(variant, "tortoiseplink")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	} else {
+		*port_option = 'p';
+		*needs_batch = 0;
+	}
+	free(variant);
+	return 1;
+}
+
+static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
+			       int *port_option, int *needs_batch)
+{
+	const char *variant;
+	char *p = NULL;
+
+	if (override_ssh_variant(port_option, needs_batch))
+		return;
+
+	if (!is_cmdline) {
+		p = xstrdup(ssh_command);
+		variant = basename(p);
+	} else {
+		const char **ssh_argv;
+
+		p = xstrdup(ssh_command);
+		if (split_cmdline(p, &ssh_argv)) {
+			variant = basename((char *)ssh_argv[0]);
+			/*
+			 * At this point, variant points into the buffer
+			 * referenced by p, hence we do not need ssh_argv
+			 * any longer.
+			 */
+			free(ssh_argv);
+		} else
+			return;
+	}
+
+	if (!strcasecmp(variant, "plink") ||
+	    !strcasecmp(variant, "plink.exe"))
+		*port_option = 'P';
+	else if (!strcasecmp(variant, "tortoiseplink") ||
+		 !strcasecmp(variant, "tortoiseplink.exe")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	}
+	free(p);
+}
+
 /*
  * This returns a dummy child_process if the transport protocol does not
  * need fork(2), or a struct child_process object if it does.  Once done,
@@ -769,7 +831,8 @@ struct child_process *git_connect(int fd[2], const char *url,
 		conn->in = conn->out = -1;
 		if (protocol == PROTO_SSH) {
 			const char *ssh;
-			int putty = 0, tortoiseplink = 0;
+			int needs_batch = 0;
+			int port_option = 'p';
 			char *ssh_host = hostandport;
 			const char *port = NULL;
 			transport_check_allowed("ssh");
@@ -792,10 +855,10 @@ struct child_process *git_connect(int fd[2], const char *url,
 			}
 
 			ssh = get_ssh_command();
-			if (!ssh) {
-				const char *base;
-				char *ssh_dup;
-
+			if (ssh)
+				handle_ssh_variant(ssh, 1, &port_option,
+						   &needs_batch);
+			else {
 				/*
 				 * GIT_SSH is the no-shell version of
 				 * GIT_SSH_COMMAND (and must remain so for
@@ -806,17 +869,10 @@ struct child_process *git_connect(int fd[2], const char *url,
 				ssh = getenv("GIT_SSH");
 				if (!ssh)
 					ssh = "ssh";
-
-				ssh_dup = xstrdup(ssh);
-				base = basename(ssh_dup);
-
-				tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
-					!strcasecmp(base, "tortoiseplink.exe");
-				putty = tortoiseplink ||
-					!strcasecmp(base, "plink") ||
-					!strcasecmp(base, "plink.exe");
-
-				free(ssh_dup);
+				else
+					handle_ssh_variant(ssh, 0,
+							   &port_option,
+							   &needs_batch);
 			}
 
 			argv_array_push(&conn->args, ssh);
@@ -824,11 +880,11 @@ struct child_process *git_connect(int fd[2], const char *url,
 				argv_array_push(&conn->args, "-4");
 			else if (flags & CONNECT_IPV6)
 				argv_array_push(&conn->args, "-6");
-			if (tortoiseplink)
+			if (needs_batch)
 				argv_array_push(&conn->args, "-batch");
 			if (port) {
-				/* P is for PuTTY, p is for OpenSSH */
-				argv_array_push(&conn->args, putty ? "-P" : "-p");
+				argv_array_pushf(&conn->args,
+						 "-%c", port_option);
 				argv_array_push(&conn->args, port);
 			}
 			argv_array_push(&conn->args, ssh_host);
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 4241ea5b32..b52b8acf98 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -386,6 +386,47 @@ test_expect_success 'tortoiseplink is like putty, with extra arguments' '
 	expect_ssh "-batch -P 123" myhost src
 '
 
+test_expect_success 'double quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="\"$TRASH_DIRECTORY/plink.exe\" -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-3 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+SQ="'"
+test_expect_success 'single quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="$SQ$TRASH_DIRECTORY/plink.exe$SQ -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-4 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	GIT_SSH_VARIANT=ssh \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-1 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'ssh.variant overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	git -c ssh.variant=ssh \
+		clone "[myhost:123]:src" ssh-bracket-clone-variant-2 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection to plink' '
+	GIT_SSH_VARIANT=plink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-3 &&
+	expect_ssh "-P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink to tortoiseplink' '
+	GIT_SSH_VARIANT=tortoiseplink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-4 &&
+	expect_ssh "-batch -P 123" myhost src
+'
+
 # Reset the GIT_SSH environment variable for clone tests.
 setup_ssh_wrapper