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/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