patch 8.2.4553: linear tag search is a bit slow

Problem:    Linear tag search is a bit slow.
Solution:   Remove a vim_ftell() call. (Yegappan Lakshmanan, closes #9937)

src/tag.c

@@ -2092,10 +2092,7 @@ findtags_get_next_line(findtags_state_T *st, tagsearch_info_T *sinfo_p)
 		eof = cs_fgets(st->lbuf, st->lbuf_size);
 	    else
 #endif
-	    {
-		sinfo_p->curr_offset = vim_ftell(st->fp);
 		eof = vim_fgets(st->lbuf, st->lbuf_size, st->fp);
-	    }
 	} while (!eof && vim_isblankline(st->lbuf));
 
 	if (eof)
@@ -2850,7 +2847,7 @@ line_read_in:
 		return;
 	    }
 
-	    if (st->state == TS_STEP_FORWARD)
+	    if (st->state == TS_STEP_FORWARD || st->state == TS_LINEAR)
 		// Seek to the same position to read the same line again
 		vim_ignored = vim_fseek(st->fp, search_info.curr_offset,
 								     SEEK_SET);

src/testdir/test_taglist.vim

@@ -259,8 +259,15 @@ func Test_tag_complete_with_overlong_line()
   call writefile(tagslines, 'Xtags')
   set tags=Xtags
 
+  " try with binary search
+  set tagbsearch
   call feedkeys(":tag inbou\<C-A>\<C-B>\"\<CR>", 'xt')
   call assert_equal('"tag inboundGSV inboundGovernor inboundGovernorCounters', @:)
+  " try with linear search
+  set notagbsearch
+  call feedkeys(":tag inbou\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"tag inboundGSV inboundGovernor inboundGovernorCounters', @:)
+  set tagbsearch&
 
   call delete('Xtags')
   set tags&

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4553,
 /**/
     4552,
 /**/