[XERCESC-1870] Xerces 2.8.0 and 3.0.1: Bug in RegularExpression::matches(txt, pMatch)

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0, 3.0.1
• Fix Version/s: 3.1.0
• Component/s: Utilities
• Environment: Platform Windows XP; MSVC 7.1, 8.0, 9.0
• Assignee: Alberto Massari
• Reporter: mark hermann
• Created: 15/May/09 14:23
• Updated: 12/Mar/18 03:02
• Resolved: 29/Jul/09 13:11

Description

RegularExpression::matches(txt, pMatch) does not work in 2.8, 3.0.1
since pMatch is not updated correctly anymore.

// Test code - works with 2.7.0

XMLCh * txt = L"2004-06-17";
Match m;
RegularExpression r("(\\-?\\d+(\\-
d

{2}(\\-
d{2}

)?)?)?(T
d

{2}(:
d{2}

(:
d

{2}(:\\d+)?)?)?)?(F\\d+)?((\\-|\\+)
d{2}

:
d

{2}

)?");
if(r.matches(txt, &m))
{
for(int i = 1; i < m.getNoGroups(); i++)
{
int i1 = m.getStartPos; // Should be 0

if(i1 < 0) // Is -1

{ printf("This is wrong!\n"); return; }

}
}

Problem can be tracked via

bool RegularExpression::matches(const XMLCh* const expression, const XMLSize_t start
, const XMLSize_t end, Match* const pMatch
, MemoryManager* const manager) const;

which does

Match* lMatch = pMatch; // use our pMatch
context.fMatch = lMatch; // put pMatch into context

/*

• Straightforward matching
  */
  for (matchStart=context.fStart; matchStart<=limit; matchStart++) { if (0 <= (matchEnd = match(&context,fOperations,matchStart))) break; }

and at the end updates the context fMatch data

if (matchEnd >= 0) {

if (context.fMatch != 0)

{ context.fMatch->setStartPos(0, (int)matchStart); context.fMatch->setEndPos(0, matchEnd); }

return true;
}

But: context.fMatch is NOT the original match pointer (pMatch), but a temporal one.
So the correct result is not propagated back to the caller anymore.