fix: track source pointers in layer/state duplication#381
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spe-ciellt merged 1 commit intogerbv:developfrom Mar 14, 2026
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The layer/state duplication logic compared currentNet->layer against lastLayer, but lastLayer is a *duplicated* pointer that will never equal a source pointer. This caused every net to create a redundant duplicate layer and state, wasting O(n) memory. Track source pointers (srcLayer, srcState) separately and compare against those to correctly detect when consecutive nets share the same layer or state, avoiding unnecessary duplication. Extracted from gerbv#163.
This was referenced Mar 7, 2026
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Summary
Fixes a comparison bug in
gerbv_image_copy_all_nets()that caused O(n) redundant layer and state allocations during image merging/export.The existing code compared
currentNet->layer != lastLayer, butlastLayerpointed to a duplicated struct — it could never equal a source pointer. Every net therefore created a new duplicate layer and state, even when consecutive nets shared the same source layer/state.srcLayer,srcState) separately from duplicated pointersgerbv_image_duplicate_layer()/gerbv_image_duplicate_state()callsThis complements PR #379 (which added
->next = NULLinitialization to the duplicate functions to prevent use-after-free on export).Attribution
Extracted from #163 (@meantaipan).
Test plan
cmake --preset linux-gnu-gcc && cmake --build build— clean buildctest -C Debug— 94/105 pass (11 pre-existing mismatches, unchanged from develop)