Item4944: EditTablePlugin data corruption under mod_perl

One of my users reported that tables on his pages are corrupted when updated by EditTablePlugin. I confirmed his claim by the page history. I looked into the code and realized that file global variables in TableEditPlugin/Core.pm are not initialized.

So I applied the following patch and since then the data corruption problem hasn't been observed.

--- lib/TWiki/Plugins/EditTablePlugin/Core.pm   2007-03-03 23:45:58.000000000 +0900
+++ lib/TWiki/Plugins/EditTablePlugin/Core.pm.patched  2007-11-09 19:01:39.000000000 +0900
@@ -28,7 +28,25 @@
             $nrCols $encodeStart $encodeEnd $table $query
            );
 
+# initialize to avoid weird problem
+sub init {
+    $preSp = undef;
+    %params = ();
+    @format = ();
+    @formatExpanded = ();
+    $prefsInitialized = undef;
+    $prefCHANGEROWS = undef;
+    $prefEDITBUTTON = undef;
+    $prefQUIETSAVE = undef;
+    $nrCols = undef;
+    $encodeStart = undef;
+    $encodeEnd = undef;
+    $table = undef;
+    $query = undef;
+}
+
 sub process {
+    init();
     $query = TWiki::Func::getCgiQuery();
     TWiki::Func::writeDebug( "- EditTablePlugin::commonTagsHandler( $_[2].$_[1] )" ) if $TWiki::Plugins::EditTablePlugin::debug;
     unless( $prefsInitialized ) {

-- TWiki:Main/HideyoImazu - 09 Nov 2007

Switching to urgent.

-- TWiki:Main.ArthurClemens - 19 Nov 2007

I have implemented this when I was working on Item3805. But a little bit different than the proposal above - I have put the initializing code inside BEGIN (to align with TablePlugin). Please review if this is sufficient.

-- TWiki:Main.ArthurClemens - 30 Nov 2007

I suspect initialization in a BEGIN block doesn't help solving the problem happening under mod_perl. SInce a BEGIN block is executed at compile time only. And the initialization is needed every time the plugin is executed.

-- TWiki:Main.HideyoImazu - 01 Dec 2007

Re-implemented as suggested.

-- TWiki:Main.ArthurClemens - 01 Dec 2007