Horton

Fix off-by-one error in PGTYPEStimestamp_fmt_asc

Tomas Vondra <tomas.vondra@postgresql.org>

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Commit: 0dafed6fedf4da0e0e38c5961ae4b1540b4a8a5c
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Date: 2019-11-30T14:04:02Z
Releases: 12.2 
Fix off-by-one error in PGTYPEStimestamp_fmt_asc

When using %b or %B patterns to format a date, the code was simply using
tm_mon as an index into array of month names. But that is wrong, because
tm_mon is 1-based, while array indexes are 0-based. The result is we
either use name of the next month, or a segfault (for December).

Fix by subtracting 1 from tm_mon for both patterns, and add a regression
test triggering the issue. Backpatch to all supported versions (the bug
is there far longer, since at least 2003).

Reported-by: Paul Spencer
Backpatch-through: 9.4
Discussion: https://postgr.es/m/16143-0d861eb8688d3fef%40postgresql.org

Files

PathChange+/−
src/interfaces/ecpg/pgtypeslib/timestamp.c modified +2 −2
src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.c modified +20 −4
src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.stderr modified +1 −1
src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.stdout modified +2 −0
src/interfaces/ecpg/test/pgtypeslib/dt_test.pgc modified +16 −0

Discussion