I just confirmed the crash.
Henson, What do you think?
Good catch by Zsolt. Your careful review is really helping a lot.
I've fixed both the prefix merge and suffix merge paths in
mergeGroupPrefixSuffix() to also increment child->max. I'll
include the fix with a regression test in the next patch series.
Regarding the suggested fix:
if (child->max != RPR_QUANTITY_INF)
child->max += 1;
While the quantifier value is int (INT32_MAX = RPR_QUANTITY_INF),
making such repetition counts practically impossible, the +1
approach is not semantically equivalent -- it could silently turn
a finite max into infinity. Instead, I took a fallback approach:
skip the merge entirely when min or max would reach
RPR_QUANTITY_INF after increment, consistent with the overflow
checks in mergeConsecutiveVars/Groups.
Good point. You are right, the plan cache should be read only.
However, Henson is working on a different approach and the code will
not be used any more...
Yes, I'm currently working on a slot-based approach (1-slot
PREV/NEXT) that won't need attno_map, so the plan cache mutation
issue will be gone.
I forggot to include the data file. Please apply attached patch on top
of v45.
Got it, thanks. By the way, how about splitting the test patch
into two -- one for sql + data files and another for expected
output files? The single test patch is getting quite large and
cfbot often fails to apply it.
Right. Maybe ERRCODE_TOO_MANY_ARGUMENTS?
I'm currently reworking PREV/NEXT to accept 2 arguments, so this
error handling will change. I'll take care of the proper error
codes along with the GROUPS typo and ERRCODE_WINDOWING_ERROR change.
Best regards,
Henson
