patch 8.2.0212: missing search/substitute pattern hardly tested

Problem:    Missing search/substitute pattern hardly tested.
Solution:   Add test_clear_search_pat() and tests. (Yegappan Lakshmanan,
            closes #5579)

Author: brammool

runtime/doc/eval.txt

@@ -2848,6 +2848,7 @@ term_wait({buf} [, {time}])	Number  wait for screen to be updated
 test_alloc_fail({id}, {countdown}, {repeat})
 				none	make memory allocation fail
 test_autochdir()		none	enable 'autochdir' during startup
+test_clear_search_pat()		none	clears the last used search pattern
 test_feedinput({string})	none	add key sequence to input buffer
 test_garbagecollect_now()	none	free memory right now for testing
 test_garbagecollect_soon()	none	free memory soon for testing

runtime/doc/testing.txt

@@ -52,6 +52,11 @@ test_autochdir()					*test_autochdir()*
 		startup has finished.
 
 
+test_clear_search_pat()				*test_clear_search_pat()*
+		Clears the last used search pattern (|/|) and the substitute
+		pattern (|:s|). This is useful for testing conditions where
+		these patterns are not set previously.
+
 test_feedinput({string})				*test_feedinput()*
 		Characters in {string} are queued for processing as if they
 		were typed by the user. This uses a low level input buffer.

runtime/doc/usr_41.txt

@@ -963,6 +963,7 @@ Testing:				    *test-functions*
 	assert_report()		report a test failure
 	test_alloc_fail()	make memory allocation fail
 	test_autochdir()	enable 'autochdir' during startup
+	test_clear_search_pat() clears the last used search pattern
 	test_override()		test with Vim internal overrides
 	test_garbagecollect_now()   free memory right now
 	test_getvalue()		get value of an internal variable

src/evalfunc.c

@@ -810,6 +810,7 @@ static funcentry_T global_functions[] =
 #endif
     {"test_alloc_fail",	3, 3, FEARG_1,	  &t_void,	f_test_alloc_fail},
     {"test_autochdir",	0, 0, 0,	  &t_void,	f_test_autochdir},
+    {"test_clear_search_pat",	0, 0, 0,  &t_void,	f_test_clear_search_pat},
     {"test_feedinput",	1, 1, FEARG_1,	  &t_void,	f_test_feedinput},
     {"test_garbagecollect_now",	0, 0, 0,  &t_void,	f_test_garbagecollect_now},
     {"test_garbagecollect_soon", 0, 0, 0, &t_void,	f_test_garbagecollect_soon},

src/proto/regexp.pro

@@ -12,6 +12,7 @@ int vim_regcomp_had_eol(void);
 regprog_T *vim_regcomp(char_u *expr_arg, int re_flags);
 void vim_regfree(regprog_T *prog);
 void free_regexp_stuff(void);
+void free_regexp_prev_sub(void);
 int regprog_in_use(regprog_T *prog);
 int vim_regexec_prog(regprog_T **prog, int ignore_case, char_u *line, colnr_T col);
 int vim_regexec(regmatch_T *rmp, char_u *line, colnr_T col);

src/proto/search.pro

@@ -9,6 +9,7 @@ void free_search_patterns(void);
 void save_last_search_pattern(void);
 void restore_last_search_pattern(void);
 char_u *last_search_pattern(void);
+void free_last_pat(int idx);
 int ignorecase(char_u *pat);
 int ignorecase_opt(char_u *pat, int ic_in, int scs);
 int pat_has_uppercase(char_u *pat);

src/proto/testing.pro

@@ -13,6 +13,7 @@ void f_assert_report(typval_T *argvars, typval_T *rettv);
 void f_assert_true(typval_T *argvars, typval_T *rettv);
 void f_test_alloc_fail(typval_T *argvars, typval_T *rettv);
 void f_test_autochdir(typval_T *argvars, typval_T *rettv);
+void f_test_clear_search_pat(typval_T *argvars, typval_T *rettv);
 void f_test_feedinput(typval_T *argvars, typval_T *rettv);
 void f_test_getvalue(typval_T *argvars, typval_T *rettv);
 void f_test_option_not_set(typval_T *argvars, typval_T *rettv);

src/regexp.c

@@ -2663,6 +2663,15 @@ free_regexp_stuff(void)
 }
 #endif
 
+/*
+ * Free the previously used substitute search pattern.
+ */
+    void
+free_regexp_prev_sub(void)
+{
+    VIM_CLEAR(reg_prev_sub);
+}
+
 #ifdef FEAT_EVAL
     static void
 report_re_switch(char_u *pat)

src/search.c

@@ -380,6 +380,12 @@ last_search_pattern(void)
 }
 #endif
 
+    void
+free_last_pat(int idx)
+{
+    VIM_CLEAR(spats[idx].pat);
+}
+
 /*
  * Return TRUE when case should be ignored for search pattern "pat".
  * Uses the 'ignorecase' and 'smartcase' options.

src/testdir/test_quickfix.vim

@@ -2718,6 +2718,10 @@ func XvimgrepTests(cchar)
   call assert_equal(0, getbufinfo('Xtestfile1')[0].loaded)
   call assert_equal([], getbufinfo('Xtestfile2'))
 
+  " Test with the last search pattern not set
+  call test_clear_search_pat()
+  call assert_fails('Xvimgrep // *', 'E35:')
+
   call delete('Xtestfile1')
   call delete('Xtestfile2')
 endfunc