patch 8.0.0147: searchpair() fails when 'magic' is off

Problem:    searchpair() does not work when 'magic' is off. (Chris Paul)
Solution:   Add \m in the pattern. (Christian Brabandt, closes #1341)

Author: brammool

src/evalfunc.c

@@ -9509,15 +9509,15 @@ do_searchpair(
 
     /* Make two search patterns: start/end (pat2, for in nested pairs) and
      * start/middle/end (pat3, for the top pair). */
-    pat2 = alloc((unsigned)(STRLEN(spat) + STRLEN(epat) + 15));
-    pat3 = alloc((unsigned)(STRLEN(spat) + STRLEN(mpat) + STRLEN(epat) + 23));
+    pat2 = alloc((unsigned)(STRLEN(spat) + STRLEN(epat) + 17));
+    pat3 = alloc((unsigned)(STRLEN(spat) + STRLEN(mpat) + STRLEN(epat) + 25));
     if (pat2 == NULL || pat3 == NULL)
 	goto theend;
-    sprintf((char *)pat2, "\\(%s\\m\\)\\|\\(%s\\m\\)", spat, epat);
+    sprintf((char *)pat2, "\\m\\(%s\\m\\)\\|\\(%s\\m\\)", spat, epat);
     if (*mpat == NUL)
 	STRCPY(pat3, pat2);
     else
-	sprintf((char *)pat3, "\\(%s\\m\\)\\|\\(%s\\m\\)\\|\\(%s\\m\\)",
+	sprintf((char *)pat3, "\\m\\(%s\\m\\)\\|\\(%s\\m\\)\\|\\(%s\\m\\)",
 							    spat, epat, mpat);
     if (flags & SP_START)
 	options |= SEARCH_START;

src/testdir/test_search.vim

@@ -279,3 +279,18 @@ func Test_use_sub_pat()
   call X()
   bwipe!
 endfunc
+
+func Test_searchpair()
+  new
+  call setline(1, ['other code here', '', '[', '" cursor here', ']'])
+  4
+  let a=searchpair('\[','',']','bW')
+  call assert_equal(3, a)
+  set nomagic
+  4
+  let a=searchpair('\[','',']','bW')
+  call assert_equal(3, a)
+  set magic
+  q!
+endfunc
+

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    147,
 /**/
     146,
 /**/