vim-patch:8.2.4805: CurSearch used for all matches in current line

Problem:    CurSearch used for all matches in current line.
Solution:   Don't use the non-zero line count. (closes vim/vim#10247)
9b36750640

src/nvim/match.c

@@ -560,6 +560,22 @@ void prepare_search_hl(win_T *wp, match_T *search_hl, linenr_T lnum)
   }
 }
 
+/// Update "shl->has_cursor" based on the match in "shl" and the cursor
+/// position.
+static void check_cur_search_hl(win_T *wp, match_T *shl)
+{
+  long linecount = shl->rm.endpos[0].lnum - shl->rm.startpos[0].lnum;
+
+  if (wp->w_cursor.lnum >= shl->lnum
+      && wp->w_cursor.lnum <= shl->lnum + shl->rm.endpos[0].lnum
+      && (wp->w_cursor.lnum > shl->lnum || wp->w_cursor.col >= shl->rm.startpos[0].col)
+      && (wp->w_cursor.lnum < shl->lnum + linecount || wp->w_cursor.col < shl->rm.endpos[0].col)) {
+    shl->has_cursor = true;
+  } else {
+    shl->has_cursor = false;
+  }
+}
+
 /// Prepare for 'hlsearch' and match highlighting in one window line.
 /// Return true if there is such highlighting and set "search_attr" to the
 /// current highlight attribute.
@@ -609,20 +625,14 @@ bool prepare_search_hl_line(win_T *wp, linenr_T lnum, colnr_T mincol, char_u **l
       } else {
         shl->endcol = MAXCOL;
       }
-      if (shl->rm.endpos[0].lnum != shl->rm.startpos[0].lnum) {
       shl->lines = shl->rm.endpos[0].lnum - shl->rm.startpos[0].lnum;
-      } else {
+      if (shl->lines == 0) {
         shl->lines = 1;
       }
 
       // check if the cursor is in the match before changing the columns
-      if (wp->w_cursor.lnum >= shl->lnum
+      if (shl == search_hl) {
-          && wp->w_cursor.lnum <= shl->lnum + shl->rm.endpos[0].lnum
+        check_cur_search_hl(wp, shl);
-          && (wp->w_cursor.lnum > shl->lnum
-              || wp->w_cursor.col >= shl->rm.startpos[0].col)
-          && (wp->w_cursor.lnum < shl->lnum + shl->lines
-              || wp->w_cursor.col < shl->rm.endpos[0].col)) {
-        shl->has_cursor = true;
       }
 
       // Highlight one character for an empty match.
@@ -723,6 +733,11 @@ int update_search_hl(win_T *wp, linenr_T lnum, colnr_T col, char_u **line, match
             shl->endcol = MAXCOL;
           }
 
+          // check if the cursor is in the match
+          if (shl == search_hl) {
+            check_cur_search_hl(wp, shl);
+          }
+
           if (shl->startcol == shl->endcol) {
             // highlight empty match, try again after it
             shl->endcol += utfc_ptr2len(*line + shl->endcol);

src/nvim/testdir/test_search.vim

@@ -951,7 +951,7 @@ func Test_hlsearch_cursearch()
 
   let lines =<< trim END
     set hlsearch scrolloff=0
-    call setline(1, ['one', 'foo', 'bar', 'baz', 'foo', 'bar'])
+    call setline(1, ['one', 'foo', 'bar', 'baz', 'foo the foo and foo', 'bar'])
     hi Search ctermbg=yellow
     hi CurSearch ctermbg=blue
   END
@@ -964,7 +964,14 @@ func Test_hlsearch_cursearch()
   call term_sendkeys(buf, "n")
   call VerifyScreenDump(buf, 'Test_hlsearch_cursearch_single_line_2', {})
 
-  call term_sendkeys(buf, "?\<CR>")
+  call term_sendkeys(buf, "n")
+  call VerifyScreenDump(buf, 'Test_hlsearch_cursearch_single_line_2a', {})
+
+  call term_sendkeys(buf, "n")
+  call VerifyScreenDump(buf, 'Test_hlsearch_cursearch_single_line_2b', {})
+
+  call term_sendkeys(buf, ":call setline(5, 'foo')\<CR>")
+  call term_sendkeys(buf, "0?\<CR>")
   call VerifyScreenDump(buf, 'Test_hlsearch_cursearch_single_line_3', {})
 
   call term_sendkeys(buf, "gg/foo\\nbar\<CR>")

test/functional/ui/searchhl_spec.lua

@@ -163,14 +163,14 @@ describe('search highlighting', function()
     end)
 
     it('works for multiline match', function()
-      command([[call setline(1, ['one', 'foo', 'bar', 'baz', 'foo', 'bar'])]])
+      command([[call setline(1, ['one', 'foo', 'bar', 'baz', 'foo the foo and foo', 'bar'])]])
       feed('gg/foo<CR>')
       screen:expect([[
         one                                     |
         {2:^foo}                                     |
         bar                                     |
         baz                                     |
-        {1:foo}                                     |
+        {1:foo} the {1:foo} and {1:foo}                     |
         bar                                     |
         /foo                                    |
       ]])
@@ -180,11 +180,32 @@ describe('search highlighting', function()
         {1:foo}                                     |
         bar                                     |
         baz                                     |
-        {2:^foo}                                     |
+        {2:^foo} the {1:foo} and {1:foo}                     |
         bar                                     |
         /foo                                    |
       ]])
-      feed('?<CR>')
+      feed('n')
+      screen:expect([[
+        one                                     |
+        {1:foo}                                     |
+        bar                                     |
+        baz                                     |
+        {1:foo} the {2:^foo} and {1:foo}                     |
+        bar                                     |
+        /foo                                    |
+      ]])
+      feed('n')
+      screen:expect([[
+        one                                     |
+        {1:foo}                                     |
+        bar                                     |
+        baz                                     |
+        {1:foo} the {1:foo} and {2:^foo}                     |
+        bar                                     |
+        /foo                                    |
+      ]])
+      command([[call setline(5, 'foo')]])
+      feed('0?<CR>')
       screen:expect([[
         one                                     |
         {2:^foo}                                     |