Fix phpdbg over-read watching an element of a packed array#160
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phpdbg watches every array element as a Bucket, but a packed array stores bare zvals, so reading Bucket.h/.key reads the adjacent element. Writing a neighbouring element then trips the watchpoint with the value unchanged: a phantom break on 32-bit, and a crash on 32-bit Windows (phpGH-22480 dropped watch_006's xfail, which exposed it). When the watched element lives in a packed array, detect relocation by re-resolving it in its parent and compare only the zval value.
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Submitted upstream as php#22756. |
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Packed arrays store bare zvals, but phpdbg watches every array element as a
Bucketand readsBucket.h/.keyin its relocation check, over-reading the neighbouring element. A sibling write then fires a phantom watchpoint, which crashed on 32-bit Windows (WINDOWS_X86_NTSin the nightly) once phpGH-22480 un-xfailedwatch_006. For a packed parent, relocation is now detected by re-resolving the element and only the zval value is compared.Note:
watch_005still carries aPHP_INT_SIZE == 4xfail with the same "flaws in the implementation of watchpoints" wording, but on a different path (string/reference indirection, not packed buckets). It likely hides a related but distinct 32-bit flaw masked by that skip; this change does not touch it, so it stays skipped.