updated for version 7.3.871
Problem:    search('^$', 'c') does not use the empty match under the cursor.
Solution:   Special handling of the 'c' flag. (Christian Brabandt)
            Add tests.
diff --git a/src/search.c b/src/search.c
index fc74680..934e4b0 100644
--- a/src/search.c
+++ b/src/search.c
@@ -727,6 +727,8 @@
 					++matchcol;
 				}
 			    }
+			    if (options & SEARCH_START)
+				break;
 			    if (ptr[matchcol] == NUL
 				    || (nmatched = vim_regexec_multi(&regmatch,
 					      win, buf, lnum + matchpos.lnum,