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authorTom Lane <tgl@sss.pgh.pa.us>2015-03-14 13:43:00 -0400
committerTom Lane <tgl@sss.pgh.pa.us>2015-03-14 13:43:00 -0400
commitdf9ebf1eeaf98481e00cd77bf6056d42310731b7 (patch)
treea713f0097a4b60e7614863ab64ed6e29e7cd0b66
parent364c006c1fba7ba7825fb06ef0166e752546f357 (diff)
downloadpostgresql-df9ebf1eeaf98481e00cd77bf6056d42310731b7.tar.gz
postgresql-df9ebf1eeaf98481e00cd77bf6056d42310731b7.zip
Remove workaround for ancient incompatibility between readline and libedit.
GNU readline defines the return value of write_history() as "zero if OK, else an errno code". libedit's version of that function used to have a different definition (to wit, "-1 if error, else the number of lines written to the file"). We tried to work around that by checking whether errno had become nonzero, but this method has never been kosher according to the published API of either library. It's reportedly completely broken in recent Ubuntu releases: psql bleats about "No such file or directory" when saving ~/.psql_history, even though the write worked fine. However, libedit has been following the readline definition since somewhere around 2006, so it seems all right to finally break compatibility with ancient libedit releases and trust that the return value is what readline specifies. (I'm not sure when the various Linux distributions incorporated this fix, but I did find that OS X has been shipping fixed versions since 10.5/Leopard.) If anyone is still using such an ancient libedit, they will find that psql complains it can't write ~/.psql_history at exit, even when the file was written correctly. This is no worse than the behavior we're fixing for current releases. Back-patch to all supported branches.
-rw-r--r--src/bin/psql/input.c17
1 files changed, 6 insertions, 11 deletions
diff --git a/src/bin/psql/input.c b/src/bin/psql/input.c
index 373013955f8..d52a3347970 100644
--- a/src/bin/psql/input.c
+++ b/src/bin/psql/input.c
@@ -382,6 +382,7 @@ static bool
saveHistory(char *fname, int max_lines)
{
#ifdef USE_READLINE
+ int errnum;
/*
* Suppressing the write attempt when HISTFILE is set to /dev/null may
@@ -405,10 +406,6 @@ saveHistory(char *fname, int max_lines)
* history from other concurrent sessions (although there are still
* race conditions when two sessions exit at about the same time). If
* we don't have those functions, fall back to write_history().
- *
- * Note: return value of write_history is not standardized across GNU
- * readline and libedit. Therefore, check for errno becoming set to
- * see if the write failed. Similarly for append_history.
*/
#if defined(HAVE_HISTORY_TRUNCATE_FILE) && defined(HAVE_APPEND_HISTORY)
{
@@ -430,9 +427,8 @@ saveHistory(char *fname, int max_lines)
nlines = Min(max_lines, history_lines_added);
else
nlines = history_lines_added;
- errno = 0;
- (void) append_history(nlines, fname);
- if (errno == 0)
+ errnum = append_history(nlines, fname);
+ if (errnum == 0)
return true;
}
#else /* don't have append support */
@@ -441,15 +437,14 @@ saveHistory(char *fname, int max_lines)
if (max_lines >= 0)
stifle_history(max_lines);
/* ... and overwrite file. Tough luck for concurrent sessions. */
- errno = 0;
- (void) write_history(fname);
- if (errno == 0)
+ errnum = write_history(fname);
+ if (errnum == 0)
return true;
}
#endif
psql_error("could not save history to file \"%s\": %s\n",
- fname, strerror(errno));
+ fname, strerror(errnum));
}
#endif