vim-patch:8.2.2694: when 'matchpairs' is empty every character beeps (#14279)

Problem:    When 'matchpairs' is empty every character beeps. (Marco Hinz)
Solution:   Bail out when no character in 'matchpairs' was found.
            (closes vim/vim#8053)  Add assert_nobeep().
https://github.com/vim/vim/commit/5b8cabfef7c3707f3e53e13844d90e5a217e1e84

5 files changed, 49 insertions, 20 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 9c3941b0fd..c9366b3bd3 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -5981,6 +5981,35 @@ static void assert_append_cmd_or_arg(garray_T *gap, typval_T *argvars,
   }
 }
 
+int assert_beeps(typval_T *argvars, bool no_beep)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const char *const cmd = tv_get_string_chk(&argvars[0]);
+  int ret = 0;
+
+  called_vim_beep = false;
+  suppress_errthrow = true;
+  emsg_silent = false;
+  do_cmdline_cmd(cmd);
+  if (no_beep ? called_vim_beep : !called_vim_beep) {
+    garray_T ga;
+    prepare_assert_error(&ga);
+    if (no_beep) {
+      ga_concat(&ga, (const char_u *)"command did beep: ");
+    } else {
+      ga_concat(&ga, (const char_u *)"command did not beep: ");
+    }
+    ga_concat(&ga, (const char_u *)cmd);
+    assert_error(&ga);
+    ga_clear(&ga);
+    ret = 1;
+  }
+
+  suppress_errthrow = false;
+  emsg_on_display = false;
+  return ret;
+}
+
 int assert_fails(typval_T *argvars)
   FUNC_ATTR_NONNULL_ALL
 {
diff --git a/src/nvim/eval.lua b/src/nvim/eval.lua
index 72168060cc..aed0824ad6 100644
--- a/src/nvim/eval.lua
+++ b/src/nvim/eval.lua
@@ -26,7 +26,7 @@ return {
     arglistid={args={0, 2}},
     argv={args={0, 2}},
     asin={args=1, func="float_op_wrapper", data="&asin"},  -- WJMc
-    assert_beeps={args={1, 2}},
+    assert_beeps={args={1}},
     assert_equal={args={2, 3}},
     assert_equalfile={args={2, 3}},
     assert_exception={args={1, 2}},
@@ -34,6 +34,7 @@ return {
     assert_false={args={1, 2}},
     assert_inrange={args={3, 4}},
     assert_match={args={2, 3}},
+    assert_nobeep={args={1}},
     assert_notequal={args={2, 3}},
     assert_notmatch={args={2, 3}},
     assert_report={args=1},
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index deeda28571..38002474af 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -391,28 +391,16 @@ static void f_argv(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   }
 }
 
+// "assert_beeps(cmd [, error])" function
 static void f_assert_beeps(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
-  const char *const cmd = tv_get_string_chk(&argvars[0]);
-  garray_T ga;
-  int ret = 0;
-
-  called_vim_beep = false;
-  suppress_errthrow = true;
-  emsg_silent = false;
-  do_cmdline_cmd(cmd);
-  if (!called_vim_beep) {
-    prepare_assert_error(&ga);
-    ga_concat(&ga, (const char_u *)"command did not beep: ");
-    ga_concat(&ga, (const char_u *)cmd);
-    assert_error(&ga);
-    ga_clear(&ga);
-    ret = 1;
-  }
+  rettv->vval.v_number = assert_beeps(argvars, false);
+}
 
-  suppress_errthrow = false;
-  emsg_on_display = false;
-  rettv->vval.v_number = ret;
+// "assert_nobeep(cmd [, error])" function
+static void f_assert_nobeep(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  rettv->vval.v_number = assert_beeps(argvars, true);
 }
 
 // "assert_equal(expected, actual[, msg])" function
diff --git a/src/nvim/search.c b/src/nvim/search.c
index 84b71d56a0..9d3d3061e4 100644
--- a/src/nvim/search.c
+++ b/src/nvim/search.c
@@ -2326,6 +2326,9 @@ showmatch(
       return;
     }
   }
+  if (*p == NUL) {
+    return;
+  }
 
   if ((lpos = findmatch(NULL, NUL)) == NULL) {  // no match, so beep
     vim_beep(BO_MATCH);
diff --git a/src/nvim/testdir/test_textformat.vim b/src/nvim/testdir/test_textformat.vim
index 4af52b536c..29f0433954 100644
--- a/src/nvim/testdir/test_textformat.vim
+++ b/src/nvim/testdir/test_textformat.vim
@@ -891,6 +891,14 @@ func Test_mps()
   bwipe!
 endfunc
 
+func Test_empty_matchpairs()
+  split
+  set matchpairs= showmatch
+  call assert_nobeep('call feedkeys("ax\tx\t\<Esc>", "xt")')
+  set matchpairs& noshowmatch
+  bwipe!
+endfunc
+
 " Test for ra on multi-byte characters
 func Test_ra_multibyte()
   new