Fix stack overflow error in recursive type alias expansion#334
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mame merged 1 commit intoruby:masterfrom Aug 12, 2025
Merged
Fix stack overflow error in recursive type alias expansion#334mame merged 1 commit intoruby:masterfrom
mame merged 1 commit intoruby:masterfrom
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This commit fixes issue ruby#324 where recursive type aliases caused SystemStackError due to infinite recursion during type expansion. The fix adds recursion detection in SigTyAliasNode#covariant_vertex0 and #contravariant_vertex0 methods by tracking the expansion stack using subst[:__expansion_stack__]. When a type alias is already being expanded, the expansion stops to prevent infinite recursion. Also adds comprehensive test cases for various recursive type alias patterns including direct recursion, mutual recursion, and generic recursive types. Fixes ruby#324 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
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To be honest, I am unsure if this fix is ok... But I will give it a try. I like the hack to exploit subst
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This commit fixes issue #324 where recursive type aliases caused SystemStackError due to infinite recursion during type expansion.
The fix adds recursion detection in SigTyAliasNode#covariant_vertex0 and #contravariant_vertex0 methods by tracking the expansion stack using subst[:expansion_stack]. When a type alias is already being expanded, the expansion stops to prevent infinite recursion.
Also adds comprehensive test cases for various recursive type alias patterns including direct recursion, mutual recursion, and generic recursive types.
Fixes #324
🤖 Generated with Claude Code