On Tue, Oct 22, 2013 at 8:58 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
So I returned from vacation only to find that the buildfarm has a bad case of acne. All the Windows members are red or pink, and have been for awhile. Sigh.
After some research I believe that I understand the reason for the CHECK failures, at least:
1. src/port/asprintf.c exhibits a truly touching faith that vsnprintf will report exactly the number of bytes that would have been required, even if the buffer is not that large. While this is what is specified in recent versions of the POSIX standard, older platforms have much sketchier behavior.
2. In particular, our own src/port/snprintf.c follows the SUS v2 rule that it should report the number of bytes it *actually wrote*. This means that asprintf.c will never think that its initial 128-byte allocation was insufficient. So, on platforms where we use this implementation (notably including Windows), the result of any asprintf call is effectively truncated at 128 bytes.
Thanks for looking at this. I had a bash and trying to figure out why vcregress check would not work last night and didn't get very far...
I can confirm that you are right just by changing the 128 into 12800 and compiling, vcregress check worked after that.
Regards
David Rowley
I have a lot of other gripes about this whole patch, but they can wait till tomorrow.
