updated for version 7.3.1071
Problem: New regexp engine: backreferences don't work correctly.
Solution: Add every possible start/end position on the state stack.
diff --git a/src/regexp.h b/src/regexp.h
index 69075b5..e609cd2 100644
--- a/src/regexp.h
+++ b/src/regexp.h
@@ -87,6 +87,7 @@
regprog_T regprog;
nfa_state_T *start;
int has_zend; /* pattern contains \ze */
+ int has_backref; /* pattern contains \1 .. \9 */
int nsubexp; /* number of () */
int nstate;
nfa_state_T state[0]; /* actually longer.. */