vim-patch:8.2.1056: wrong display when mixing match conceal and syntax conceal

Problem:    Wrong display when mixing match conceal and syntax conceal.
Solution:   Adjust how conceal flags are used. (closes vim/vim#6327, closes vim/vim#6303)
211dd3fd82

src/nvim/screen.c

@@ -2082,7 +2082,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
   int line_attr_lowprio = 0;            // low-priority attribute for the line
   matchitem_T *cur;                     // points to the match list
   match_T     *shl;                     // points to search_hl or a match
-  int shl_flag;                         // flag to indicate whether search_hl
+  bool shl_flag;                        // flag to indicate whether search_hl
                                         // has been processed or not
   bool prevcol_hl_flag;                 // flag to indicate whether prevcol
                                         // equals startcol of search_hl or one
@@ -2950,16 +2950,15 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
          */
         v = (long)(ptr - line);
         cur = wp->w_match_head;
-        shl_flag = FALSE;
+        shl_flag = false;
-        while (cur != NULL || shl_flag == FALSE) {
+        while (cur != NULL || !shl_flag) {
-          if (shl_flag == FALSE
+          if (!shl_flag
-              && ((cur != NULL
+              && (cur == NULL || cur->priority > SEARCH_HL_PRIORITY)) {
-                   && cur->priority > SEARCH_HL_PRIORITY)
-                  || cur == NULL)) {
             shl = &search_hl;
-            shl_flag = TRUE;
+            shl_flag = true;
-          } else
+          } else {
             shl = &cur->hl;
+          }
           if (cur != NULL) {
             cur->pos.cur = 0;
           }
@@ -2984,7 +2983,7 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
                 has_match_conc = v == (long)shl->startcol ? 2 : 1;
                 match_conc = cur->conceal_char;
               } else {
-                has_match_conc = match_conc = 0;
+                has_match_conc = 0;
               }
             } else if (v == (long)shl->endcol) {
               shl->attr_cur = 0;
@@ -3026,16 +3025,15 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
         search_attr_from_match = false;
         search_attr = search_hl.attr_cur;
         cur = wp->w_match_head;
-        shl_flag = FALSE;
+        shl_flag = false;
-        while (cur != NULL || shl_flag == FALSE) {
+        while (cur != NULL || !shl_flag) {
-          if (shl_flag == FALSE
+          if (!shl_flag
-              && ((cur != NULL
+              && (cur == NULL || cur->priority > SEARCH_HL_PRIORITY)) {
-                   && cur->priority > SEARCH_HL_PRIORITY)
-                  || cur == NULL)) {
             shl = &search_hl;
-            shl_flag = TRUE;
+            shl_flag = true;
-          } else
+          } else {
             shl = &cur->hl;
+          }
           if (shl->attr_cur != 0) {
             search_attr = shl->attr_cur;
             search_attr_from_match = shl != &search_hl;
@@ -3678,12 +3676,13 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
                && vim_strchr(wp->w_p_cocu, 'v') == NULL)) {
         char_attr = conceal_attr;
         if ((prev_syntax_id != syntax_seqnr || has_match_conc > 1)
-            && (syn_get_sub_char() != NUL || match_conc
+            && (syn_get_sub_char() != NUL
+                || (has_match_conc && match_conc)
                 || wp->w_p_cole == 1)
             && wp->w_p_cole != 3) {
           // First time at this concealed item: display one
           // character.
-          if (match_conc) {
+          if (has_match_conc && match_conc) {
             c = match_conc;
           } else if (syn_get_sub_char() != NUL) {
             c = syn_get_sub_char();
@@ -3843,16 +3842,15 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow,
           // 'search_hl' and the match list.
           char_attr = search_hl.attr;
           cur = wp->w_match_head;
-          shl_flag = FALSE;
+          shl_flag = false;
-          while (cur != NULL || shl_flag == FALSE) {
+          while (cur != NULL || !shl_flag) {
-            if (shl_flag == FALSE
+            if (!shl_flag
-                && ((cur != NULL
+                && (cur == NULL || cur->priority > SEARCH_HL_PRIORITY)) {
-                     && cur->priority > SEARCH_HL_PRIORITY)
-                    || cur == NULL)) {
               shl = &search_hl;
-              shl_flag = TRUE;
+              shl_flag = true;
-            } else
+            } else {
               shl = &cur->hl;
+            }
             if ((ptr - line) - 1 == (long)shl->startcol
                 && (shl == &search_hl || !shl->is_addpos)) {
               char_attr = shl->attr;

src/nvim/testdir/test_matchadd_conceal.vim

@@ -59,9 +59,9 @@ func Test_matchadd_and_conceallevel_3()
   setlocal filetype=conf
   syntax on
 
-  1put='# This is a Test'
+  1put='# This is a Test  $'
-  "             1234567890123456
+  "             1234567890123
-  let expect = '#ThisisaTest'
+  let expect = '#ThisisaTest$'
 
   call cursor(1, 1)
   call matchadd('Conceal', '\%2l ', 10, -1, {'conceal': 'X'})
@@ -69,22 +69,25 @@ func Test_matchadd_and_conceallevel_3()
   let lnum = 2
   call assert_equal(expect, Screenline(lnum))
   call assert_equal(screenattr(lnum, 1), screenattr(lnum, 2))
-  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 7))
-  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 10))
-  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 12))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 13))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 14))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 16))
 
   " more matchadd()
-  "             1234567890123456
+  "             12345678901234
-  let expect = '#Thisisa Test'
+  let expect = '#Thisisa Test$'
 
   call matchadd('ErrorMsg', '\%2l Test', 20, -1, {'conceal': 'X'})
   redraw!
   call assert_equal(expect, Screenline(lnum))
   call assert_equal(screenattr(lnum, 1) , screenattr(lnum, 2))
-  call assert_equal(screenattr(lnum, 2) , screenattr(lnum, 7))
+  call assert_equal(screenattr(lnum, 1) , screenattr(lnum, 7))
   call assert_notequal(screenattr(lnum, 1) , screenattr(lnum, 10))
-  call assert_equal(screenattr(lnum, 10), screenattr(lnum, 12))
+  call assert_equal(screenattr(lnum, 10), screenattr(lnum, 13))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 14))
   call assert_notequal(screenattr(lnum, 1) , screenattr(lnum, 16))
   call assert_notequal(screenattr(lnum, 10), screenattr(lnum, 16))
 
@@ -132,15 +135,18 @@ func Test_syn_and_match_conceal()
   new
   setlocal concealcursor=n conceallevel=1
 
-  1put='# This is a Test'
+  1put='# This is a Test  '
-  "             1234567890123456
-  let expect = '#ZThisZisZaZTest'
 
-  call cursor(1, 1)
-  call matchadd('Conceal', '\%2l ', 10, -1, {'conceal': 'Z'})
-  syntax match MyConceal /\%2l / conceal containedin=ALL cchar=*
-  redraw!
   let lnum = 2
+  call cursor(1, 1)
+
+  "             123456789012345678
+  let expect = '#ZThisZisZaZTestZZ'
+  call matchadd('Conceal', '\%2l ', 10, -1, {'conceal': 'Z'})
+  syntax match MyConceal /\%2l / conceal containedin=ALL
+  hi MyConceal ctermbg=4 ctermfg=2
+  redraw!
+
   call assert_equal(expect, Screenline(lnum))
   call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
@@ -148,8 +154,19 @@ func Test_syn_and_match_conceal()
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
   call assert_equal(screenattr(lnum, 1), screenattr(lnum, 16))
 
-  "             1234567890123456
+  syntax clear MyConceal
-  let expect = '#*This*is*a*Test'
+  syntax match MyConceal /\%2l / conceal containedin=ALL cchar=*
+  redraw!
+
+  call assert_equal(expect, Screenline(lnum))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 16))
+
+  "             123456789012345678
+  let expect = '#*This*is*a*Test**'
   call clearmatches()
   redraw!
 
@@ -160,6 +177,48 @@ func Test_syn_and_match_conceal()
   call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
   call assert_equal(screenattr(lnum, 1), screenattr(lnum, 16))
 
+  "             123456789012345678
+  let expect = '#*ThisXis*a*Test**'
+  call matchadd('Conceal', '\%2l\%7c ', 10, -1, {'conceal': 'X'})
+  redraw!
+
+  call assert_equal(expect, Screenline(lnum))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 7))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 10))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
+  call assert_equal(screenattr(lnum, 1), screenattr(lnum, 16))
+
+  "             123456789012345678
+  let expect = '#*ThisXis*a*Test**'
+  call matchadd('ErrorMsg', '\%2l Test', 20, -1)
+  redraw!
+
+  call assert_equal(expect, Screenline(lnum))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
+  call assert_notequal(screenattr(lnum, 12), screenattr(lnum, 13))
+  call assert_equal(screenattr(lnum, 13), screenattr(lnum, 16))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 17))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 18))
+  call assert_notequal(screenattr(lnum, 18), screenattr(lnum, 19))
+
+  "             123456789012345678
+  let expect = '# ThisXis a Test'
+  syntax clear MyConceal
+  syntax match MyConceal /\%2l / conceal containedin=ALL
+  redraw!
+
+  call assert_equal(expect, Screenline(lnum))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 2))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 12))
+  call assert_notequal(screenattr(lnum, 1), screenattr(lnum, 12))
+  call assert_notequal(screenattr(lnum, 12), screenattr(lnum, 13))
+  call assert_equal(screenattr(lnum, 13), screenattr(lnum, 16))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 17))
+  call assert_equal(screenattr(lnum, 2), screenattr(lnum, 18))
+  call assert_notequal(screenattr(lnum, 18), screenattr(lnum, 19))
+
   syntax off
   quit!
 endfunc