<div dir="ltr">Thanks, Martin, Ludo,<div><br></div><div>Sorry for taking so long to respond. I have rewritten a large section of my code which accounts for the delay.<div class="gmail_extra"><br><br><div class="gmail_quote">
On 29 June 2013 01:01, Martin <span dir="ltr"><<a href="mailto:lazarus@mfriebe.de" target="_blank">lazarus@mfriebe.de</a>></span> wrote:<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div>
<br></div>
Maybe memory got corrupted at some point before, then errors can happen at seemingly random locations.<br></blockquote><div> </div><div>I have had issues with using TStringLists in the past, specifically with passing a TStringList as an argument to (or returning from) a function. </div>
<div>So I have rewritten my code to try to avoid doing this.</div><div><br></div><div>Basically I am reading a large Blob from a (Firebird) Database into a TStringList which has been declared as a global variable. This is the only Tstringlist.</div>
<div><br></div><div>This list contains commands for a vector graphic which is rendered, first on a Image buffer TBitmap and then copied (CopyRect) onto the Canvas of a Picture component.</div><div><br></div>
<div>The first pass works fine. The GlobalList is cleared and the Blob loaded and then rendered.</div><div><br></div><div>Selecting another Database entry also works fine: The globallist is cleared and reloaded from the new database entry, the scale is recalculated and the drawing is rendered correctly.</div>
<div><br></div><div>I can pan around the drawing as well.</div><div><br></div><div>However, I am using the Mousewheel to zoom in and out to enlarge portions of the drawing and this is where I am getting the SIGFPE.</div>
<div><br></div><div style>After my using the Mousewheel (up or down), the application performs the zoom without error, but, on the first movement of the mouse, the SIGFPE occurs.</div><div style><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
Check your dbg setup <a href="http://wiki.lazarus.freepascal.org/Debugger_Setup" target="_blank">http://wiki.lazarus.<u></u>freepascal.org/Debugger_Setup</a><br>
<br>
use all avaailable compiler checks<br>
-Criot<br>
-gh (heaptrace/linking)<br>
-gt<br>
<br>
<br>
What does the stack window show?<br></blockquote><div><br></div><div>0042A8D5 751a jne 0x42a8f1</div><div>0042A8D7 8b450c mov 0xc(%ebp),%eax</div><div>0042A8DA a3b0e26700 mov %eax,0x67e2b0</div>
<div>0042A8DF 8b4508 mov 0x8(%ebp),%eax</div><div>0042A8E2 a3b4e26700 mov %eax,0x67e2b4</div><div>0042A8E7 c705e0e2670001000000 movl $0x1,0x67e2e0</div><div>0042A8F1 c9 leave </div>
<div>0042A8F2 c20c00 ret $0xc</div><div>0042A8F5 0000 add %al,(%eax)</div><div>0042A8F7 0000 add %al,(%eax)</div><div>0042A8F9 0000 add %al,(%eax)</div>
<div>0042A8FB 0000 add %al,(%eax)</div><div>0042A8FD 0000 add %al,(%eax)</div><div>0042A8FF 005589 add %dl,-0x77(%ebp)</div><div>0042A902 e583 in $0x83,%eax</div>
<div>0042A904 ec in (%dx),%al</div><div>0042A905 64895d9c mov %ebx,%fs:-0x64(%ebp)</div><div>0042A909 8975a0 mov %esi,-0x60(%ebp)</div><div>0042A90C 897da4 mov %edi,-0x5c(%ebp)</div>
<div>0042A90F 8945f4 mov %eax,-0xc(%ebp)</div><div>0042A912 8955fc mov %edx,-0x4(%ebp)</div><div>0042A915 894df8 mov %ecx,-0x8(%ebp)</div><div>0042A918 d9ee fldz <----------------------------------------- Exception raised here.</div>
<div><div>0042A91A dd0580e26700 fldl 0x67e280</div><div>0042A920 ded9 fcompp </div><div>0042A922 dfe0 fnstsw %ax</div><div>0042A924 9e sahf </div>
<div>0042A925 0f841b010000 je 0x42aa46</div><div>0042A92B 8b450c mov 0xc(%ebp),%eax</div><div>0042A92E a300e36700 mov %eax,0x67e300</div><div>0042A933 8b4508 mov 0x8(%ebp),%eax</div>
<div>0042A936 a304e36700 mov %eax,0x67e304</div></div><div><br></div><div style>Regards,</div><div style><br></div><div style>Dave</div></div></div></div></div>