PCRE limit workaround for old PHP versions (#119)

darcs-hash:20050207171920-9977f-2ad8f85cf4e4488e93cd686fec99b6c10ecbad73.gz

1 files changed, 12 insertions, 3 deletions

diff --git a/inc/common.php b/inc/common.php
index a1325e2fc..e9c4d7406 100644
--- a/inc/common.php
+++ b/inc/common.php
@@ -330,9 +330,18 @@ function checkwordblock(){
   if(!$conf['usewordblock']) return false;
 
   $blockfile = file('conf/wordblock.conf');
-  //read file in chunks of 600 - this should work around the
-  //MAX_PATTERN_SIZE in PCRE
-  while($blocks = array_splice($blockfile,0,600)){
+  //how many lines to read at once (to work around some PCRE limits)
+  if(version_compare(phpversion(),'4.3.0','<')){
+    //old versions of PCRE define a maximum of parenthesises even if no
+    //backreferences are used - the maximum is 99
+    //this is very bad performancewise and may even be too high still
+    $chunksize = 40; 
+  }else{
+    //read file in chunks of 600 - this should work around the
+    //MAX_PATTERN_SIZE in modern PCRE
+    $chunksize = 600;
+  }
+  while($blocks = array_splice($blockfile,0,$chunksize)){
     $re = array();
     #build regexp from blocks
     foreach($blocks as $block){