Hi, Sergey,

thanks for the patch! LGTM with a minor comment below.

Sergey

On 3/6/26 16:42, Sergey Kaplun wrote:

From: Mike Pall <mike>

Contributed by XmiliaH.

(cherry picked from commit af9763a50da87ff8ba16e828cbd5664135e05a88)

The generated ADD/SUB IRs for the calculation of indexes in the string
for the aforementioned build-ins don't check the overflow. This may lead

s/build-ins/built-ins/

to the incorrect results, incorrect trace semantics, or invalid memory
access. Also, the negative values may pass the UGT guard check emitted
for the positive `end` position and lead to the incorrect results on the
trace.

This patch fixes this by using guarded ADDOV/SUBOV instead. The UGT IR
is replaced with GT.

Sergey Kaplun:
* added the description and the test for the problem

Part of tarantool/tarantool#12134
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