Composing with ZWJ

[dov imagic weizmann ac il]

I have been trying to use ZWJ in the Hebrew render module in order
to break a kerning rule a Hebrew character and an accent. But I 
haven't been able to get the module to receive the ZWJ character at
all. Even though I did the following modification:

     static PangoEngineRange hebrew_ranges[] = {
       { 0x0591, 0x05f4, "*" },  /* Hebrew */
>      { 0x200B, 0x200F, "*" },  /* zerowidth space to left-to-right */
     };

and

  if (font_info->type != HEBREW_FONT_NONE)
    {
      gunichar wc;
      
      for (wc = 0x590; wc <= 0x5f4; wc++)
	pango_coverage_set (result, wc, PANGO_COVERAGE_EXACT);
      
>      for (wc = 0x200b; wc <= 0x200f; wc++)
>	pango_coverage_set (result, wc, PANGO_COVERAGE_EXACT);
    }

the hebrew_engine_shape() function never receives the ZWJ character.
Instead if the ZWJ in the middle of a Hebrew range, then 
hebrew_engine_shape() is called twice with two ranges on both sides
of the ZWJ character.

So how can make the Hebrew module receive ZWJ?

Regards,
Dov