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[PATCH] mergesort: avoid left shift overflow

From
René Scharfe <l.s.r@web.de>
Date
Nov 15, 2021, 23:19 UTC
Message-ID
<5eabbe1c-4c0f-559a-da21-423afec89e7e@web.de>

Use size_t to match n when building the bitmask for checking whether a rank is occupied, instead of the default signed int.

Signed-off-by: René Scharfe <l.s.r@web.de>
---
Ugh, sorry. :(
 mergesort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mergesort.c b/mergesort.c
index 6216835566..bd9c6ef8ee 100644
--- a/mergesort.c
+++ b/mergesort.c
@@ -63,7 +63,7 @@ void *llist_mergesort(void *list,
 		void *next = get_next_fn(list);
 		if (next)
 			set_next_fn(list, NULL);
-		for (i = 0; n & (1 << i); i++)
+		for (i = 0; n & ((size_t)1 << i); i++)
 			list = llist_merge(ranks[i], list, get_next_fn,
 					   set_next_fn, compare_fn);
 		n++;
--
2.33.1
Next: Johannes Schindelin
Message 1 of 10 in “mergesort: avoid left shift overflow”
  1. mergesort: avoid left shift overflowRené Scharfe, Nov 15, 2021
  2. Johannes SchindelinNov 16, 2021
  3. Junio C HamanoNov 17, 2021
  4. Johannes SchindelinNov 17, 2021
  5. Philip OakleyNov 18, 2021
  6. Johannes SchindelinNov 19, 2021
  7. René ScharfeNov 19, 2021
  8. Philip OakleyNov 19, 2021
  9. Junio C HamanoNov 19, 2021
  10. Philip OakleyNov 19, 2021

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