Don't fail on libpq-generated error reports in pg_amcheck.

An error PGresult generated by libpq itself, such as a report of
connection loss, won't have broken-down error fields.
should_processing_continue() blithely assumed that
PG_DIAG_SEVERITY_NONLOCALIZED would always be present, and would
dump core if it wasn't.

Per grepping to see if 6d157e7cb's mistake was repeated elsewhere.

diff --git a/src/bin/pg_amcheck/pg_amcheck.c b/src/bin/pg_amcheck/pg_amcheck.c
index f0b818e987ae33ac90043ee964048eb1fed92d74..3cff319f0257987b9b9c180681ecfa4679f2efef 100644 (file)
--- a/src/bin/pg_amcheck/pg_amcheck.c
+++ b/src/bin/pg_amcheck/pg_amcheck.c
@@ -930,6 +930,8 @@ should_processing_continue(PGresult *res)
            /* This is expected but requires closer scrutiny */
        case PGRES_FATAL_ERROR:
            severity = PQresultErrorField(res, PG_DIAG_SEVERITY_NONLOCALIZED);
+           if (severity == NULL)
+               return false;   /* libpq failure, probably lost connection */
            if (strcmp(severity, "FATAL") == 0)
                return false;
            if (strcmp(severity, "PANIC") == 0)