Re: Bug in error reporting for multi-line JSON

Simon Riggs <simon(dot)riggs(at)enterprisedb(dot)com> writes:
> JSON parsing reports the line number and relevant context info
> incorrectly when the JSON contains newlines. Current code mostly just
> says "LINE 1" and is misleading for error correction. There were no
> tests for this previously.

Couple thoughts:

* I think you are wrong to have removed the line number bump that
happened when report_json_context advances context_start over a
newline. The case is likely harder to get to now, but it can still
happen can't it? If it can't, we should remove that whole stanza.

* I'd suggest naming the new JsonLexContext field "pos_last_newline";
"linefeed" is not usually the word we use for this concept. (Although
actually, it might work better if you make that point to the char
*after* the newline, in which case "last_linestart" might be the
right name.)

* I'm not enthused about back-patching. This behavior seems like an
improvement, but that doesn't mean people will appreciate changing it
in stable branches.

regards, tom lane