Fix POSIX API bug when REG_STARTEND is used with a non-zero starting …

…offset and

there are unset groups within the matching group list.


git-svn-id: svn:https://vcs.exim.org/pcre/code/trunk@1724 2f5784b3-3f2a-0410-8824-cb99058d5e15

ChangeLog

@@ -4,7 +4,7 @@ ChangeLog for PCRE
 Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
 development is happening in the PCRE2 10.xx series.
 
-Version 8.42 xx-xxx-2017
+Version 8.42 xx-xxx-2018
 ------------------------
 
 1. Fixed a MIPS issue in the JIT compiler reported by Joshua Kinard.
@@ -39,6 +39,11 @@ as the first character of a match.
 8. Fix out-of-bounds read for partial matching of /./ against an empty string
 when the newline type is CRLF.
 
+9. When matching using the the REG_STARTEND feature of the POSIX API with a 
+non-zero starting offset, unset capturing groups with lower numbers than a
+group that did capture something were not being correctly returned as "unset" 
+(that is, with offset values of -1).
+
 
 Version 8.41 05-July-2017
 -------------------------

pcreposix.c

@@ -6,7 +6,7 @@
 and semantics are as close as possible to those of the Perl 5 language.
 
  Written by Philip Hazel
- Copyright (c) 1997-2017 University of Cambridge
+ Copyright (c) 1997-2018 University of Cambridge
 
 -----------------------------------------------------------------------------
 Redistribution and use in source and binary forms, with or without
@@ -389,8 +389,8 @@ if (rc >= 0)
  {
  for (i = 0; i < (size_t)rc; i++)
  {
- pmatch[i].rm_so = ovector[i*2] + so;
- pmatch[i].rm_eo = ovector[i*2+1] + so;
+ pmatch[i].rm_so = (ovector[i*2] < 0)? -1 : ovector[i*2] + so;
+ pmatch[i].rm_eo = (ovector[i*2+1] < 0)? -1: ovector[i*2+1] + so;
  }
  if (allocated_ovector) free(ovector);
  for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;