updated for version 7.3.1127

Problem:    No error for using empty \%[].
Solution:   Give error message.

src/regexp.c

@@ -366,7 +366,7 @@ static char_u e_z_not_allowed[] = N_("E66: \\z( not allowed here");
 static char_u e_z1_not_allowed[] = N_("E67: \\z1 et al. not allowed here");
 #endif
 static char_u e_missing_sb[] = N_("E69: Missing ] after %s%%[");
-
+static char_u e_empty_sb[]  = N_("E70: Empty %s%%[]");
 #define NOT_MULTI	0
 #define MULTI_ONE	1
 #define MULTI_MULT	2
@@ -2227,7 +2227,7 @@ regatom(flagp)
 				      return NULL;
 			      }
 			      if (ret == NULL)
-				  EMSG2_RET_NULL(_("E70: Empty %s%%[]"),
+				  EMSG2_RET_NULL(_(e_empty_sb),
 						      reg_magic == MAGIC_ALL);
 			      lastbranch = regnode(BRANCH);
 			      br = regnode(NOTHING);

src/regexp_nfa.c

@@ -977,6 +977,9 @@ nfa_regatom()
 						      reg_magic == MAGIC_ALL);
 			    EMIT(c);
 			}
+			if (n == 0)
+			    EMSG2_RET_FAIL(_(e_empty_sb),
+						      reg_magic == MAGIC_ALL);
 			EMIT(NFA_OPT_CHARS);
 			EMIT(n);
 			break;

src/version.c

@@ -728,6 +728,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1127,
 /**/
     1126,
 /**/