Hello R-devel,
Some inputs cause sort(method="radix") to try to read vectors at index
-1, which is caught for character vectors on some builds that use clang
-fsanitize=address since r89198:
podman run --rm -it \
registry.gitlab.com/rdatatable/dockerfiles/r-devel-clang-san \
R -q -s -e "order(NA_character_, 'c', method = 'radix', na.last = NA)"
# Error in order(NA_character_, "c", method = "radix", na.last = NA) :
# attempt access index -1/1 in STRING_ELT
Since savetl_end() did not run, some CHARSXPs retain their altered
TRUELENGTHs. The R session is then likely to crash when it tries to
read a negative-numbered hash bucket (usually during install() while
lazy-loading bytecode for another function call, e.g., when wrapping
the order() call in try()).
This seems to be a matter of catching elements already sorted as NA on
a previous pass:
Index: src/main/radixsort.c
===================================================================
--- src/main/radixsort.c (revision 89211)
+++ src/main/radixsort.c (working copy)
@@ -1766,7 +1766,9 @@
// this edge case had to be taken care of
// here.. (see the bottom of this file for
// more explanation)
- switch (TYPEOF(x)) {
+ if (o[i] == 0) { // already sorted as NA
+ isSorted = false;
+ } else switch (TYPEOF(x)) {
case INTSXP:
if (INTEGER(x)[o[i] - 1] == NA_INTEGER) {
isSorted = false;
I don't entirely understand what causes src/main/radixsort.c to call
the non-inlined version of STRING_ELT in some cases.
--
Best regards,
Ivan
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