bug#7012: 24.0.50; bidi: crash while selecting region using mouse in X11

[Thamer Mahmoud <thamer.mahmoud@gmail.com>]

I think this crash may be a font-related issue, as I can't reproduce
it while using Microsoft Core fonts (Times New Roman, Courier New,
etc).

I also did some testing with a virtual Windows XP (through QEMU), and
the crash is reproducible there.  I just had to choose the font
"Courier" from the "Set Default Font" dialogue, then select the
content of the testcase.

Eli Zaretskii writes:
 > So you press and hold the left mouse button when the mouse pointer is
 > near the bottom of the window, and then move the mouse upward, is that
 > right?
 > 

Yes, just by moving the pointer towards the Arabic text form any point
below the testcase contents.

 > Please show me the entire contents of the buffer in this case.  "In
 > the middle of a buffer" is too ambiguous for me to try to reproduce
 > this.
 > 

The testcase should work.  I had only two extra blank lines below it
just to make it easier to move the cursor upwards.

 > > Moreover, this crash seems specific to Arabic and reordered Latin text
 > > using RLM (like the above example).  I couldn't reproduce this using
 > > Hebrew.
 > 
 > I tried with the text you sent with the report, not with Hebrew.

I know. But a Hebrew testcase is sometimes useful when tracking bugs
with Arabic, especially to decide whether a bug is in Bidi or in some
Arabic-specific code (like shaping, LAM-ALEF handling, etc).  In any
case, it wasn't reproducible using Hebrew because it was rendered with
"Courier New".

-- 
Thamer