git p4: handle servers without move support

Support for the "p4 move" command was added in 8e9497c (git p4:
add support for 'p4 move' in P4Submit, 2012-07-12), which checks
to make sure that the client and server support the command.

But older versions of p4d may not handle the "-k" argument, and
newer p4d allow disabling "p4 move" with a configuration setting.
Check for both these cases by testing a p4 move command on bogus
filenames and looking for strings in the error messages.

Reported-by: Vitor Antunes <vitor.hda@gmail.com>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-p4.py

@@ -129,6 +129,25 @@ def p4_has_command(cmd):
     p.communicate()
     return p.returncode == 0
 
+def p4_has_move_command():
+    """See if the move command exists, that it supports -k, and that
+       it has not been administratively disabled.  The arguments
+       must be correct, but the filenames do not have to exist.  Use
+       ones with wildcards so even if they exist, it will fail."""
+
+    if not p4_has_command("move"):
+        return False
+    cmd = p4_build_cmd(["move", "-k", "@from", "@to"])
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    (out, err) = p.communicate()
+    # return code will be 1 in either case
+    if err.find("Invalid option") >= 0:
+        return False
+    if err.find("disabled") >= 0:
+        return False
+    # assume it failed because @... was invalid changelist
+    return True
+
 def system(cmd):
     expand = isinstance(cmd,basestring)
     if verbose:
@@ -894,7 +913,7 @@ def __init__(self):
         self.conflict_behavior = None
         self.isWindows = (platform.system() == "Windows")
         self.exportLabels = False
-        self.p4HasMoveCommand = p4_has_command("move")
+        self.p4HasMoveCommand = p4_has_move_command()
 
     def check(self):
         if len(p4CmdList("opened ...")) > 0:

t/t9814-git-p4-rename.sh

@@ -199,6 +199,41 @@ test_expect_success 'detect copies' '
 	)
 '
 
+# See if configurables can be set, and in particular if the run.move.allow
+# variable exists, which allows admins to disable the "p4 move" command.
+test_expect_success 'p4 configure command and run.move.allow are available' '
+	p4 configure show run.move.allow >out ; retval=$? &&
+	test $retval = 0 &&
+	{
+		egrep ^run.move.allow: out &&
+		test_set_prereq P4D_HAVE_CONFIGURABLE_RUN_MOVE_ALLOW ||
+		true
+	} || true
+'
+
+# If move can be disabled, turn it off and test p4 move handling
+test_expect_success P4D_HAVE_CONFIGURABLE_RUN_MOVE_ALLOW \
+		    'do not use p4 move when administratively disabled' '
+	test_when_finished "p4 configure set run.move.allow=1" &&
+	p4 configure set run.move.allow=0 &&
+	(
+		cd "$cli" &&
+		echo move-disallow-file >move-disallow-file &&
+		p4 add move-disallow-file &&
+		p4 submit -d "add move-disallow-file"
+	) &&
+	test_when_finished cleanup_git &&
+	git p4 clone --dest="$git" //depot &&
+	(
+		cd "$git" &&
+		git config git-p4.skipSubmitEdit true &&
+		git config git-p4.detectRenames true &&
+		git mv move-disallow-file move-disallow-file-moved &&
+		git commit -m "move move-disallow-file" &&
+		git p4 submit
+	)
+'
+
 test_expect_success 'kill p4d' '
 	kill_p4d
 '