string.c: guard tmp in rb_str_format_m#16280
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XrXr merged 2 commits intoruby:masterfrom Mar 2, 2026
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Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format.
it's intended to be used to extend the liverange of a VALUE
byroot
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
byroot
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
byroot
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
k0kubun
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
hsbt
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
luke-gru
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[Bug #21931] Keep tmp alive while RARRAY_CONST_PTR(tmp) is used by rb_str_format. [alan: sunk the guard below usage] Reviewed-by: Alan Wu <XrXr@users.noreply.github.com>
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The
tmpin rb_str_format_m should be guarded byRB_GC_GUARD.This script reproduces the crash:
segfault.txt
rb_str_format_mpassesRARRAY_CONST_PTR(tmp)torb_str_format. Without an explicit GC guard, compiler optimization can maketmpappear dead too early while the derived pointer is still in use inrb_str_format.This PR adds the
RB_GC_GUARDcall.