updated for version 7.4.045

Problem:    substitute() does not work properly when the pattern starts with
            "\ze".
Solution:   Detect an empty match. (Christian Brabandt)

src/eval.c

@@ -24301,6 +24301,7 @@ do_string_sub(str, pat, sub, flags)
     garray_T	ga;
     char_u	*ret;
     char_u	*save_cpo;
+    int		zero_width;
 
     /* Make 'cpoptions' empty, so that the 'l' flag doesn't work here */
     save_cpo = p_cpo;
@@ -24339,20 +24340,17 @@ do_string_sub(str, pat, sub, flags)
 	    (void)vim_regsub(&regmatch, sub, (char_u *)ga.ga_data
 					  + ga.ga_len + i, TRUE, TRUE, FALSE);
 	    ga.ga_len += i + sublen - 1;
-	    /* avoid getting stuck on a match with an empty string */
+	    zero_width = (tail == regmatch.endp[0]
-	    if (tail == regmatch.endp[0])
+				    || regmatch.startp[0] == regmatch.endp[0]);
+	    tail = regmatch.endp[0];
+	    if (*tail == NUL)
+		break;
+	    if (zero_width)
 	    {
-		if (*tail == NUL)
+		/* avoid getting stuck on a match with an empty string */
-		    break;
 		*((char_u *)ga.ga_data + ga.ga_len) = *tail++;
 		++ga.ga_len;
 	    }
-	    else
-	    {
-		tail = regmatch.endp[0];
-		if (*tail == NUL)
-		    break;
-	    }
 	    if (!do_all)
 		break;
 	}

src/testdir/test80.in

@@ -142,6 +142,8 @@ STARTTEST
 :$put =substitute('C', 'C', 'c', '')
 :$put =substitute('D', 'D', '%', '')
 /^TEST_7
+ENDTEST
+
 TEST_7:
 
 STARTTEST

src/testdir/test80.ok

@@ -103,6 +103,8 @@ TEST_7:
 k
 l
 l
+
+
 TEST_5:
 A123456789987654321
 

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    45,
 /**/
     44,
 /**/