[PATCH] comctl32/tooltips: Protect TTM_ADDTOOLW from invalid text pointers

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://testbot.winehq.org/JobDetails.pl?Key=22377

Your paranoid android.


=== wxppro (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w2003std (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== wvistau64 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w2008s64 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w7u (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w7pro64 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w8 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w864 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w1064 (32 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== wvistau64 (64 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w2008s64 (64 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w7pro64 (64 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w864 (64 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!

=== w1064 (64 bit tooltips) ===
tooltips.c:471: Test failed: Adding the tool to the tooltip failed!