psql: Catch and report errors while printing result table

Errors (for example I/O errors or disk full) while printing out result
tables were completely ignored, which could result in silently
truncated output in scripts, for example.  Fix by adding some basic
error checking and reporting.

Author: Daniel Verite <daniel@manitou-mail.org>
Author: David Zhang <david.zhang@highgo.ca>
Discussion: https://www.postgresql.org/message-id/flat/9a0b3c8d-ee14-4b1d-9d0a-2c993bdabacc@manitou-mail.org

diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 67df0cd2c7764a3d4bd103a8288c3e5f88920251..396a40089ce0de7da2fc02d2d2fe169743b85ed0 100644 (file)
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -708,6 +708,7 @@ static bool
 PrintQueryTuples(const PGresult *results)
 {
    printQueryOpt my_popt = pset.popt;
+   bool result = true;
 
    /* one-shot expanded output requested via \gx */
    if (pset.g_expanded)
@@ -725,6 +726,11 @@ PrintQueryTuples(const PGresult *results)
            disable_sigpipe_trap();
 
        printQuery(results, &my_popt, fout, false, pset.logfile);
+       if (ferror(fout))
+       {
+           pg_log_error("could not print result table: %m");
+           result = false;
+       }
 
        if (is_pipe)
        {
@@ -735,9 +741,16 @@ PrintQueryTuples(const PGresult *results)
            fclose(fout);
    }
    else
+   {
        printQuery(results, &my_popt, pset.queryFout, false, pset.logfile);
+       if (ferror(pset.queryFout))
+       {
+           pg_log_error("could not print result table: %m");
+           result = false;
+       }
+   }
 
-   return true;
+   return result;
 }