patch 8.2.2694: when 'matchpairs' is empty every character beeps

Problem:    When 'matchpairs' is empty every character beeps. (Marco Hinz)
Solution:   Bail out when no character in 'matchpairs' was found.
            (closes #8053)  Add assert_nobeep().

runtime/doc/eval.txt

@@ -2440,6 +2440,7 @@ assert_inrange({lower}, {upper}, {actual} [, {msg}])
 				Number	assert {actual} is inside the range
 assert_match({pat}, {text} [, {msg}])
 				Number	assert {pat} matches {text}
+assert_nobeep({cmd})		Number	assert {cmd} does not cause a beep
 assert_notequal({exp}, {act} [, {msg}])
 				Number	assert {exp} is not equal {act}
 assert_notmatch({pat}, {text} [, {msg}])

runtime/doc/testing.txt

@@ -243,7 +243,8 @@ test_srand_seed([seed])					*test_srand_seed()*
 assert_beeps({cmd})					*assert_beeps()*
 		Run {cmd} and add an error message to |v:errors| if it does
 		NOT produce a beep or visual bell.
-		Also see |assert_fails()| and |assert-return|.
+		Also see |assert_fails()|, |assert_nobeep()| and
+		|assert-return|.
 
 		Can also be used as a |method|: >
 			GetCmd()->assert_beeps()
@@ -376,6 +377,14 @@ assert_match({pattern}, {actual} [, {msg}])
 
 		Can also be used as a |method|: >
 			getFile()->assert_match('foo.*')
+<
+assert_nobeep({cmd})					*assert_nobeep()*
+		Run {cmd} and add an error message to |v:errors| if it
+		produces a beep or visual bell.
+		Also see |assert_beeps()|.
+
+		Can also be used as a |method|: >
+			GetCmd()->assert_nobeep()
 <
 							*assert_notequal()*
 assert_notequal({expected}, {actual} [, {msg}])

src/evalfunc.c

@@ -739,6 +739,8 @@ static funcentry_T global_functions[] =
 			ret_number_bool,    f_assert_inrange},
     {"assert_match",	2, 3, FEARG_2,	    NULL,
 			ret_number_bool,    f_assert_match},
+    {"assert_nobeep",	1, 2, FEARG_1,	    NULL,
+			ret_number_bool,    f_assert_nobeep},
     {"assert_notequal",	2, 3, FEARG_2,	    NULL,
 			ret_number_bool,    f_assert_notequal},
     {"assert_notmatch",	2, 3, FEARG_2,	    NULL,

src/proto/testing.pro

@@ -1,5 +1,6 @@
 /* testing.c */
 void f_assert_beeps(typval_T *argvars, typval_T *rettv);
+void f_assert_nobeep(typval_T *argvars, typval_T *rettv);
 void f_assert_equal(typval_T *argvars, typval_T *rettv);
 void f_assert_equalfile(typval_T *argvars, typval_T *rettv);
 void f_assert_notequal(typval_T *argvars, typval_T *rettv);

src/search.c

@@ -2817,6 +2817,8 @@ showmatch(
 	if (*p == NUL)
 	    return;
     }
+    if (*p == NUL)
+	return;
 
     if ((lpos = findmatch(NULL, NUL)) == NULL)	    // no match, so beep
 	vim_beep(BO_MATCH);

src/testdir/test_textformat.vim

@@ -858,6 +858,14 @@ func Test_mps_latin1()
   close!
 endfunc
 
+func Test_empty_matchpairs()
+  split
+  set matchpairs= showmatch
+  call assert_nobeep('call feedkeys("ax\tx\t\<Esc>", "xt")')
+  set matchpairs& noshowmatch
+  bwipe!
+endfunc
+
 func Test_mps_error()
   let encoding_save = &encoding
 

src/testing.c

@@ -338,7 +338,7 @@ assert_append_cmd_or_arg(garray_T *gap, typval_T *argvars, char_u *cmd)
 }
 
     static int
-assert_beeps(typval_T *argvars)
+assert_beeps(typval_T *argvars, int no_beep)
 {
     char_u	*cmd = tv_get_string_chk(&argvars[0]);
     garray_T	ga;
@@ -348,10 +348,13 @@ assert_beeps(typval_T *argvars)
     suppress_errthrow = TRUE;
     emsg_silent = FALSE;
     do_cmdline_cmd(cmd);
-    if (!called_vim_beep)
+    if (no_beep ? called_vim_beep : !called_vim_beep)
     {
 	prepare_assert_error(&ga);
-	ga_concat(&ga, (char_u *)"command did not beep: ");
+	if (no_beep)
+	    ga_concat(&ga, (char_u *)"command did beep: ");
+	else
+	    ga_concat(&ga, (char_u *)"command did not beep: ");
 	ga_concat(&ga, cmd);
 	assert_error(&ga);
 	ga_clear(&ga);
@@ -369,7 +372,16 @@ assert_beeps(typval_T *argvars)
     void
 f_assert_beeps(typval_T *argvars, typval_T *rettv)
 {
-    rettv->vval.v_number = assert_beeps(argvars);
+    rettv->vval.v_number = assert_beeps(argvars, FALSE);
+}
+
+/*
+ * "assert_nobeep(cmd [, error])" function
+ */
+    void
+f_assert_nobeep(typval_T *argvars, typval_T *rettv)
+{
+    rettv->vval.v_number = assert_beeps(argvars, TRUE);
 }
 
 /*

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2694,
 /**/
     2693,
 /**/