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sas7bcat: compare block pointers three-way instead of subtracting #420

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Merged
evanmiller merged 1 commit into from
Oct 27, 2026
Merged

sas7bcat: compare block pointers three-way instead of subtracting #420

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5 changes: 4 additions & 1 deletion src/sas/readstat_sas7bcat_read.c
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Original file line number Diff line number Diff line change
Expand Up @@ -296,7 +296,10 @@ static readstat_error_t sas7bcat_augment_index(const char *index, size_t len, sa
static int compare_block_pointers(const void *elem1, const void *elem2) {
uint64_t v1 = *(const uint64_t *)elem1;
uint64_t v2 = *(const uint64_t *)elem2;
return v1 - v2;
/* The values pack a page number into the high 32 bits, so a plain
* subtraction truncated to int loses that half and misorders (or reports
* as equal) pointers on different pages. Compare three-way instead. */
return (v1 > v2) - (v1 < v2);
}

static void sas7bcat_sort_index(sas7bcat_ctx_t *ctx) {
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