[JSC] Infinite loop in for...in after r280760

[Xan Lopez]

This is at least observable in the JS LayoutTest reserved-words.js. The following fix seems to take care of it:

diff --git a/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp b/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp
index 3940a4e9afd3..113a7d9e191e 100644
--- a/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp
+++ b/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp
@@ -13440,6 +13440,7 @@ void SpeculativeJIT::compileEnumeratorNextUpdateIndexAndMode(Node* node)
         m_jit.or64(scratch.gpr(), resultRegs.payloadGPR());
 #else
         m_jit.move(TrustedImm32(JSPropertyNameEnumerator::IndexedMode), resultRegs.tagGPR());
+        m_jit.or32(scratch.gpr(), resultRegs.payloadGPR());
 #endif
 
         jsValueResult(resultRegs, node);

[Xan Lopez]

Created attachment 436384 [details]
v1

[Xan Lopez]

Created attachment 436390 [details]
v2

[Yusuke Suzuki]

Comment on attachment 436390 [details]
v2

r=me

[EWS]

Committed r281571 (240935@main): <https://commits.webkit.org/240935@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 436390 [details].

[Radar WebKit Bug Importer]

<rdar://problem/82350525>