mirror of
https://github.com/postgres/postgres.git
synced 2025-05-31 03:21:24 +03:00
45bfef7fba
These functions are stated to be Oracle-compatible, but they weren't. Yugo Nagata noticed that while our code returns zero for a zero or negative fourth parameter (occur_index), Oracle throws an error. Further testing by me showed that there was also a discrepancy in the interpretation of a negative third parameter (beg_index): Oracle thinks that a negative beg_index indicates the last place where the target substring can *begin*, whereas our code thinks it is the last place where the target can *end*. Adjust the sample code to behave like Oracle in both these respects. Also change it to be a CDATA[] section, simplifying copying-and-pasting out of the documentation source file. And fix minor problems in the introductory comment, which wasn't very complete or accurate. Back-patch to all supported branches. Although this patch only touches documentation, we should probably call it out as a bug fix in the next minor release notes, since users who have adopted the functions will likely want to update their versions. Yugo Nagata and Tom Lane Discussion: https://postgr.es/m/20171229191705.c0b43a8c.nagata@sraoss.co.jp