Make escaping functions retain trailing bytes of an invalid character. Instead of dropping the trailing byte(s) of an invalid or incomplete multibyte character, replace only the first byte with a known-invalid sequence, and process the rest normally. This seems less likely to confuse incautious callers than the behavior adopted in 5dc1e42b4.
While we're at it, adjust PQescapeStringInternal to produce at most one bleat about invalid multibyte characters per string. This matches the behavior of PQescapeInternal, and avoids the risk of producing tons of repetitive junk if a long string is simply given in the wrong encoding. This is a followup to the fixes for CVE-2025-1094, and should be included if cherry-picking those fixes. Author: Andres Freund <and...@anarazel.de> Co-authored-by: Tom Lane <t...@sss.pgh.pa.us> Reported-by: Jeff Davis <pg...@j-davis.com> Discussion: https://postgr.es/m/20250215012712...@rfd.leadboat.com Backpatch-through: 13 Branch ------ REL_16_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/991a60a9f23bd2b160e223c46bb2ae1db58f738a Modified Files -------------- src/fe_utils/string_utils.c | 91 ++++++++++++++++-------------------------- src/interfaces/libpq/fe-exec.c | 69 ++++++++++++++------------------ 2 files changed, 65 insertions(+), 95 deletions(-)
