git p4: RCS expansion should not span newlines

This bug was introduced in cb585a9 (git-p4: keyword
flattening fixes, 2011-10-16).  The newline character
is indeed special, and $File$ expansions should not try
to match across multiple lines.

Based-on-patch-by: Chris Goard <cgoard@gmail.com>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Jeff King <peff@peff.net>

git-p4.py

@@ -227,7 +227,7 @@ def p4_keywords_regexp_for_type(base, type_mods):
         pattern = r"""
             \$              # Starts with a dollar, followed by...
             (%s)            # one of the keywords, followed by...
-            (:[^$]+)?       # possibly an old expansion, followed by...
+            (:[^$\n]+)?     # possibly an old expansion, followed by...
             \$              # another dollar
             """ % kwords
         return pattern

t/t9810-git-p4-rcs.sh

@@ -155,6 +155,25 @@ test_expect_success 'cleanup after failure' '
 	)
 '
 
+# perl $File:: bug check
+test_expect_success 'ktext expansion should not expand multi-line $File::' '
+	(
+		cd "$cli" &&
+		cat >lv.pm <<-\EOF
+		my $wanted = sub { my $f = $File::Find::name;
+				    if ( -f && $f =~ /foo/ ) {
+		EOF
+		p4 add -t ktext lv.pm &&
+		p4 submit -d "lv.pm"
+	) &&
+	test_when_finished cleanup_git &&
+	git p4 clone --dest="$git" //depot &&
+	(
+		cd "$git" &&
+		test_cmp "$cli/lv.pm" lv.pm
+	)
+'
+
 #
 # Do not scrub anything but +k or +ko files.  Sneak a change into
 # the cli file so that submit will get a conflict.  Make sure that