patch 8.0.0049
Problem:    When a match ends in part of concealed text highlighting, it might
            mess up concealing by resetting prev_syntax_id.
Solution:   Do not reset prev_syntax_id and add a test to verify. (Christian
            Brabandt, closes #1092)
diff --git a/src/screen.c b/src/screen.c
index 78f89eb..c98d567 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -3981,9 +3981,6 @@
 			else if (v == (long)shl->endcol)
 			{
 			    shl->attr_cur = 0;
-#ifdef FEAT_CONCEAL
-			    prev_syntax_id = 0;
-#endif
 			    next_search_hl(wp, shl, lnum, (colnr_T)v,
 					       shl == &search_hl ? NULL : cur);
 			    pos_inprogress = cur == NULL || cur->pos.cur == 0
diff --git a/src/testdir/test_matchadd_conceal.vim b/src/testdir/test_matchadd_conceal.vim
index 5da2816..610917f 100644
--- a/src/testdir/test_matchadd_conceal.vim
+++ b/src/testdir/test_matchadd_conceal.vim
@@ -264,3 +264,25 @@
 
   quit!
 endfunction
+
+function! Test_matchadd_and_syn_conceal()
+  new
+  let cnt='Inductive bool : Type := | true : bool | false : bool.'
+  let expect = 'Inductive - : Type := | true : - | false : -.'
+  0put =cnt
+  " set filetype and :syntax on to change screenattr()
+  set cole=1 cocu=nv
+  hi link CheckedByCoq WarningMsg
+  syntax on
+  syntax keyword coqKwd bool conceal cchar=-
+  redraw!
+  call assert_equal(expect, s:screenline(1))
+  call assert_notequal(screenattr(1, 10) , screenattr(1, 11))
+  call assert_notequal(screenattr(1, 11) , screenattr(1, 12))
+  call assert_equal(screenattr(1, 11) , screenattr(1, 32))
+  call matchadd('CheckedByCoq', '\%<2l\%>9c\%<16c')
+  call assert_equal(expect, s:screenline(1))
+  call assert_notequal(screenattr(1, 10) , screenattr(1, 11))
+  call assert_notequal(screenattr(1, 11) , screenattr(1, 12))
+  call assert_equal(screenattr(1, 11) , screenattr(1, 32))
+endfunction
diff --git a/src/version.c b/src/version.c
index 81de3d0..6fdf9f4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    49,
+/**/
     48,
 /**/
     47,