patch 9.1.0428: Tag guessing leaves wrong search history with very short names

Problem:  Tag guessing leaves wrong search history with very short names
          (after 9.1.0426).
Solution: Use the correct variable for pattern length (zeertzjq).

closes: #14817

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/tag.c

@@ -3945,7 +3945,7 @@ jumpto_tag(
 			// Guess again: "^char * \<func  ("
 			pbuflen = vim_snprintf((char *)pbuf, LSIZE, "^\\[#a-zA-Z_]\\.\\*\\<%s\\s\\*(",
 								tagp.tagname);
-			if (!do_search(NULL, '/', '/', pbuf, len, (long)1,
+			if (!do_search(NULL, '/', '/', pbuf, pbuflen, (long)1,
 							 search_options, NULL))
 			    found = 0;
 		    }

src/testdir/test_tagjump.vim

@@ -1560,4 +1560,22 @@ func Test_tagbsearch()
   set tags& tagbsearch&
 endfunc
 
+" Test tag guessing with very short names
+func Test_tag_guess_short()
+  call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
+        \ "y\tXf\t/^y()/"],
+        \ 'Xt', 'D')
+  set tags=Xt cpoptions+=t
+  call writefile(['', 'int * y () {}', ''], 'Xf', 'D')
+
+  let v:statusmsg = ''
+  let @/ = ''
+  ta y
+  call assert_match('E435:', v:statusmsg)
+  call assert_equal(2, line('.'))
+  call assert_match('<y', @/)
+
+  set tags& cpoptions-=t
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    428,
 /**/
     427,
 /**/