diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 24948a2..cb49112 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -2603,6 +2603,44 @@
   call assert_equal('prolog', &filetype)
   bwipe!
 
+  " IDL
+  call writefile(['x = findgen(100)/10'], 'Xfile.pro', 'D')
+  split Xfile.pro
+  call assert_equal('idlang', &filetype)
+
+  filetype off
+endfunc
+
+
+func Test_pl_file()
+  filetype on
+
+  "Prolog
+  call writefile([':-module(test/1,'], 'Xfile.pl', 'D')
+  split Xfile.pl
+  call assert_equal('prolog', &filetype)
+  bwipe!
+
+  call writefile(['% comment'], 'Xfile.pl', 'D')
+  split Xfile.pl
+  call assert_equal('prolog', &filetype)
+  bwipe!
+
+  call writefile(['/* multiline comment'], 'Xfile.pl', 'D')
+  split Xfile.pl
+  call assert_equal('prolog', &filetype)
+  bwipe!
+
+  call writefile(['rule(test, 1.7).'], 'Xfile.pl', 'D')
+  split Xfile.pl
+  call assert_equal('prolog', &filetype)
+  bwipe!
+
+  " Perl
+  call writefile(['%data = (1, 2, 3);'], 'Xfile.pl', 'D')
+  split Xfile.pl
+  call assert_equal('perl', &filetype)
+
   filetype off
 endfunc
 
diff --git a/src/version.c b/src/version.c
index 5473fe0..5393649 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    602,
+/**/
     601,
 /**/
     600,