Previous FIRSTLINE patch was broken. Fix it.

git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@900 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 11 insertions, 16 deletions

diff --git a/src/pcre2_dfa_match.c b/src/pcre2_dfa_match.c
index 9c1d805..65243bf 100644
--- a/src/pcre2_dfa_match.c
+++ b/src/pcre2_dfa_match.c
@@ -3363,8 +3363,6 @@ for (;;)
   if ((re->overall_options & PCRE2_NO_START_OPTIMIZE) == 0 &&
       (options & PCRE2_DFA_RESTART) == 0)
     {
-    PCRE2_SPTR save_end_subject = end_subject;
-
     /* If firstline is TRUE, the start of the match is constrained to the first
     line of a multiline string. That is, the match must be before or at the
     first newline following the start of matching. Temporarily adjust
@@ -3388,13 +3386,6 @@ for (;;)
       else
 #endif
       while (t < end_subject && !IS_NEWLINE(t)) t++;
-
-      /* Note that we only need to advance by one code unit if we found a
-      newline. If the newline is CRLF, a first code unit of LF should not
-      match, because it is not at or before the newline. Similarly, only the
-      first code unit of a Unicode newline might be relevant. */
-
-      if (t < end_subject) t++;
       end_subject = t;
       }
 
@@ -3466,14 +3457,18 @@ for (;;)
 #endif
           }
 
-        /* If we can't find the required code unit, break the bumpalong loop,
-        to force a match failure, except when doing partial matching, when we
-        let the next cycle run at the end of the subject. To see why, consider
-        the pattern /(?<=abc)def/, which partially matches "abc", even though
-        the string does not contain the starting character "d". */
+        /* If we can't find the required code unit, having reached the true end
+        of the subject, break the bumpalong loop, to force a match failure,
+        except when doing partial matching, when we let the next cycle run at
+        the end of the subject. To see why, consider the pattern /(?<=abc)def/,
+        which partially matches "abc", even though the string does not contain
+        the starting character "d". If we have not reached the true end of the
+        subject (PCRE2_FIRSTLINE caused end_subject to be temporarily modified)
+        we also let the cycle run, because the matching string is legitimately
+        allowed to start with the first code unit of a newline. */
 
         if ((mb->moptions & (PCRE2_PARTIAL_HARD|PCRE2_PARTIAL_SOFT)) == 0 &&
-            start_match >= end_subject)
+            start_match >= mb->end_subject)
           break;
         }
 
@@ -3532,7 +3527,7 @@ for (;;)
 
     /* Restore fudged end_subject */
 
-    end_subject = save_end_subject;
+    end_subject = mb->end_subject;
 
     /* The following two optimizations are disabled for partial matching. */