fix: sizeof(pointer) bug in addfile and UB in context() shifts#33
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fix: sizeof(pointer) bug in addfile and UB in context() shifts#33
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Two bugs fixed in MD5.xs: 1. addfile() used sizeof(buffer) for PerlIO_read length, but when USE_HEAP_INSTEAD_OF_STACK is defined, buffer is a pointer — so sizeof gives 4 or 8 instead of 4096, degrading read performance ~500-1000x. Replaced with a BUFFER_SIZE constant. 2. context() restore used bare byte shifts like buf[3]<<24 without casting to U32 first. When the byte has bit 7 set, this shifts into the sign bit of a signed int — undefined behavior per C standard. Added (U32) casts to match the existing s2u() macro pattern used elsewhere in the file. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Docker Hub has removed perl:5.8 through perl:5.24 container images, causing CI failures on all branches including main. Replace the container-based approach with shogo82148/actions-setup-perl which builds Perl from source and supports 5.8+. Changes: - Switch linux matrix from Docker containers to actions-setup-perl - Update actions/checkout v2 -> v4 - Update install-with-cpm v1 -> stable (ubuntu job) - Add Perl 5.34, 5.36, 5.38, 5.40 to test matrix - Drop Perl 5.8 (22 years old, minimal practical value) - Add Windows CI job (Strawberry Perl via actions-setup-perl) - Add macOS CI job (system perl, no container) - Limit AUTHOR_TESTING/RELEASE_TESTING to ubuntu job only Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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What
Fixes two latent bugs in MD5.xs — a sizeof misuse and undefined behavior in byte shifts.
Why
addfile()usessizeof(buffer)for the read loop length. WhenUSE_HEAP_INSTEAD_OF_STACKis defined,bufferis a pointer, sosizeofyields 4 or 8 instead of 4096 — the read loop would degrade to reading a few bytes at a time.context()restore reconstructs U32 state values with bare shifts likebuf[3]<<24. Theunsigned charpromotes to signedint, so when bit 7 is set, this shifts into the sign bit — undefined behavior per C standard. Thes2u()macro on line 111 already handles this correctly with(U32)casts.How
BUFFER_SIZEconstant (4096) used in both the stack array declaration and the heap allocation + read call.(U32)casts to all byte shifts incontext()restore, matching the existings2u()pattern.Testing
All 316 tests pass. Updated hardcoded MD5 hash in
t/files.t.🤖 Generated with Claude Code
Quality Report
Changes: 2 files changed, 9 insertions(+), 8 deletions(-)
Code scan: clean
Tests: passed (OK)
Branch hygiene: clean
Generated by Kōan post-mission quality pipeline