Fix bad auto-possessify for certain classes.

git-svn-id: svn:https://vcs.exim.org/pcre/code/trunk@1738 2f5784b3-3f2a-0410-8824-cb99058d5e15

ChangeLog

@@ -27,6 +27,11 @@ ported from PCRE2).
 
 4. Typo LCC_ALL for LC_ALL fixed in pcregrep.
 
+5. In a pattern such as /[^\x{100}-\x{ffff}]*[\x80-\xff]/ which has a repeated
+negative class with no characters less than 0x100 followed by a positive class
+with only characters less than 0x100, the first class was incorrectly being 
+auto-possessified, causing incorrect match failures.
+
 
 Version 8.42 20-March-2018
 --------------------------

pcre_compile.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) 1997-2016 University of Cambridge
+ Copyright (c) 1997-2018 University of Cambridge
 
 -----------------------------------------------------------------------------
 Redistribution and use in source and binary forms, with or without
@@ -3299,7 +3299,7 @@ for(;;)
  if ((*xclass_flags & XCL_MAP) == 0)
  {
  /* No bits are set for characters < 256. */
- if (list[1] == 0) return TRUE;
+ if (list[1] == 0) return (*xclass_flags & XCL_NOT) == 0;
  /* Might be an empty repeat. */
  continue;
  }

testdata/testinput4

@@ -727,4 +727,7 @@
 /\C(\W?ſ)'?{{/8
  \\C(\\W?ſ)'?{{
 
+/[^\x{100}-\x{ffff}]*[\x80-\xff]/8
+ \x{99}\x{99}\x{99}
+
 /-- End of testinput4 --/

testdata/testoutput4

@@ -1277,4 +1277,8 @@ No match
  \\C(\\W?ſ)'?{{
 No match
 
+/[^\x{100}-\x{ffff}]*[\x80-\xff]/8
+ \x{99}\x{99}\x{99}
+ 0: \x{99}\x{99}\x{99}
+
 /-- End of testinput4 --/