Fix GH-17144: type inference narrowing on ZEND_FETCH_DIM_W#22
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Fix GH-17144: type inference narrowing on ZEND_FETCH_DIM_W#22
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FETCH_DIM_W stripped MAY_BE_ARRAY_EMPTY only when key_type had valid key bits. When the key operand's type widened across loop iterations (from MAY_BE_ARRAY to include scalar types), key_type transitioned from 0 to non-zero, causing MAY_BE_ARRAY_EMPTY to be stripped on the second pass but not the first. This violated monotonicity. Strip MAY_BE_ARRAY_EMPTY for write opcodes (W, RW, LIST_W) regardless of key_type, since a dimension write makes the array non-empty. Closes phpGH-17144
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Promoted to php#21674. |
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Summary
FETCH_DIM_WstrippedMAY_BE_ARRAY_EMPTYonly inside a block guarded bykey_type & (MAY_BE_ARRAY_KEY_LONG|MAY_BE_ARRAY_KEY_STRING). When the key operand's type widened across loop iterations (e.g. fromMAY_BE_ARRAYto include scalar types),key_typewent from 0 to non-zero, causing the flag to be stripped on the second pass but not the first. This violated monotonicity and triggered the narrowing assertion.Strips
MAY_BE_ARRAY_EMPTYfor write opcodes (W, RW, LIST_W) regardless ofkey_type, since a dimension write makes the array non-empty.Fixes php#17144