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Date: Wed, 24 May 2006 03:41:37 -0700
From: Brian Dessent <brian AT dessent DOT net>
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Subject: Re: 1.5.19: changes have broken Qt3
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clayne AT anodized DOT com wrote:

> Actually, is this really a fault in gdb? Cygwin is throwing a SIGSEGV signal,
> correct? GDB does what it's told, stops on SIGSEGV by default.

Not really.  In cases where it is checking parameters or otherwise
expects to dereference an invalid pointer, Cygwin installs a temporary
fault handler that intercepts any fault and returns the correct error
code.  If you run such code outside of gdb you get no indication of a
fault at all, just like a standard try/except block -- unlike an actual
segmentation violation where the program is terminated.  So yes, it is a
defect that gdb treats these as actual SIGSEGVs when they are actually
just part of how Cygwin works internally, and this misperception has
caused countless messages posted to this list insisting that there is
some kind of problem in Cygwin where there is none.

Brian

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