[Bug 4311] Crash on a loft command with incorrect input.

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Re: [Bug 4311] Crash on a loft command with incorrect input.

Post by chennes »

This is a bug in OpenCascade (and is still present in 7.5.0). In BRepOffsetAPI_ThruSections.cxx, lines 482-499 are

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try {
    // Calculate the resulting shape
    if (myWires.Length() == 2 || myIsRuled) {
      // create a ruled shell
    else {
      // create a smoothed shell
  catch (Standard_Failure const&)
  // Encode the Regularities
When you only have the first two sections selected, it creates a ruled surface. This fails due to a zero-length normal, which throws an exception. That exception is nicely caught, calls NotDone(), and returns without ever calling BRepLib::EncodeRegularity(myShape);. However, CreateSmoothed() fails without an exception, it just returns when it detects that it can't make the shell. So the catch is never hit, and EncodeRegularity is called. It proceeds to try to use the TShape without ever checking it for null. And we die.

Is this something we should try to code around by doing our own detection, or just file an upstream bug report?
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Re: [Bug 4311] Crash on a loft command with incorrect input.

Post by chrisb »

Moved to developers corner.
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Re: [Bug 4311] Crash on a loft command with incorrect input.

Post by Kunda1 »

Hi @chennes, thanks for posting. Just a quick request. Please link back tot he bug using the bug bbcode in your OP.
Example: issue #4311. This makes it more convenient and helps keep forum threads about bugs organized.
My bad! it was part of a longer post. duh :oops: Please disregard
Thanks again!

Edit: my bad
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