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

tglsfdc · tglsfdc · commit 51da231597a9 · 2022-06-06T11:26:57.000-04:00
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 6d157e7's mistake was repeated elsewhere.
diff --git 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)
