Avoid double allocation when joining To/Cc headers#58
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Folding repeated To:/Cc: headers built a throwaway buffer with
emalloc + strcpy + two strcat calls, then handed it to
add_assoc_string, which copied it again into a zend_string before the
temporary was freed. That is two allocations and two copies per fold.
Build the joined value directly into a single zend_string with memcpy
and store it with add_assoc_str, which takes ownership. One allocation,
one copy. Output ("a, b, c") is unchanged.
remicollet
requested changes
Jun 12, 2026
header_val is null-terminated, so copying add_len + 1 bytes pulls in its NUL and makes the separate ZSTR_VAL(joined)[...] = '\0' assignment redundant. zend_string_alloc already reserves the +1 byte for it. Suggested by @remicollet in review of phpGH-58.
remicollet
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Jun 13, 2026
header_val is null-terminated, so copying add_len + 1 bytes pulls in its NUL and makes the separate ZSTR_VAL(joined)[...] = '\0' assignment redundant. zend_string_alloc already reserves the +1 byte for it. Suggested by @remicollet in review of GH-58.
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Folding repeated
To:/Cc:headers built a throwaway buffer withemalloc+strcpy+ twostrcatcalls, then handed it toadd_assoc_string, which copied it again into azend_string— two allocations and two copies per fold. Build the joined value once, directly into azend_stringviamemcpy, and store it withadd_assoc_str, which takes ownership. One allocation, one copy; output is unchanged.