On Wed, Aug 29, 2018 at 1:31 PM, Amit Kapila <amit.kapil...@gmail.com> wrote:
> While trying to debug a recent bug report on hash indexes [1], I > noticed that pg_verify_checksums don't work on Windows (or at least in > my environment). > > initdb -k ..\..\data > pg_verify_checksums.exe ..\..\Data > pg_verify_checksums: short read of block 0 in file > "..\..\Data/global/1136", got only 15 bytes > > I have debugged and found that below code is the culprit. > > scan_file(char *fn, int segmentno) > { > .. > f = open(fn, 0); > .. > int r = read(f, buf, BLCKSZ); > > if (r == 0) > break; > > if (r != BLCKSZ) > { > fprintf(stderr, _("%s: short read of block %d in file \"%s\", got only > %d bytes\n"), > progname, blockno, fn, r); > exit(1); > } > .. > } > > We are opening the file in text mode and trying to read the BLCKSZ > bytes, however, if there is any Control-Z char, it is treated as EOF. > This problem has been mentioned in the comments in c.h as follows: > /* > * NOTE: this is also used for opening text files. > * WIN32 treats Control-Z as EOF in files opened in text mode. > * Therefore, we open files in binary mode on Win32 so we can read > * literal control-Z. The other affect is that we see CRLF, but > * that is OK because we can already handle those cleanly. > */ > > So, I think we need to open the file in binary mode as in other parts > of the code. The attached patch fixes the problem for me. > > Thoughts? > Yikes. Yes, I believe you are correct, and that looks like the correct fix. I wonder why this was not caught on the buildfarm. We do have regression tests for it, AFAIK? Or maybe we just lucked out there because there was no ^Z char in the files there? -- Magnus Hagander Me: https://www.hagander.net/ <http://www.hagander.net/> Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>