export_vrml: Fix 3D model destination timestamp check

Not all hosts have `wxHAS_HUGE_FILES` enabled, which causes us to drop
millisecond resolution accuracy. In some cases, this can cause
race-conditions with externally generated components such as by KiBot
(which generates THT components with color bands on the fly), which runs
so fast, that we fall within a second resolution.

When setting the destination timestamp, there's only two valid options.
Either the destination file exists, and if it does, we use the
destination file's timestamp (current behavior) or it does not exist, in
which case we should use an 'invalid' (null, NaN, whatever).

Calling the constructor sets this up correctly and then only setting the
timestamp if the file exists. Nothing else.

Signed-off-by: Olliver Schinagl <[email protected]>

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/20877

pcbnew/exporters/exporter_vrml.cpp

@@ -1127,9 +1127,7 @@ void EXPORTER_PCB_VRML::ExportVrmlFootprint( FOOTPRINT* aFootprint, std::ostream
 
             // copy the file if necessary
             wxDateTime srcModTime = srcFile.GetModificationTime();
-            wxDateTime destModTime = srcModTime;
-
-            destModTime.SetToCurrent();
+            wxDateTime destModTime = wxDateTime();
 
             if( dstFile.FileExists() )
                 destModTime = dstFile.GetModificationTime();