Don't call PQclear until the struct is really no longer going to be used.

alvherre · alvherre · commit 117d73a9e7af · 2006-05-28T17:23:29.000Z
Per Coverity bug #304.  Thanks to Martijn van Oosterhout for reporting it.

Zero out the pointer fields of PGresult so that these mistakes are more
easily catched, per discussion.
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
  *	by PostgreSQL
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.434 2006/05/26 23:48:54 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.435 2006/05/28 17:23:29 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1445,16 +1445,15 @@ dumpStdStrings(Archive *AH)
 
 		check_sql_result(res, g_conn, qry->data, PGRES_TUPLES_OK);
 
-		PQclear(res);
-
 		resetPQExpBuffer(qry);
 
 		std_strings = (strcmp(PQgetvalue(res, 0, 0), "on") == 0);
 		appendPQExpBuffer(qry, "SET standard_conforming_strings = ");
 		appendStringLiteral(qry, PQgetvalue(res, 0, 0), true, !std_strings);
 		appendPQExpBuffer(qry, ";\n");
 		puts(PQgetvalue(res, 0, 0));
-		
+
+		PQclear(res);
 	}
 	
 	ArchiveEntry(AH, nilCatalogId, createDumpId(),
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.184 2006/05/23 22:13:19 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.185 2006/05/28 17:23:29 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -364,6 +364,12 @@ PQclear(PGresult *res)
 	if (res->tuples)
 		free(res->tuples);
 
+	/* zero out the pointer fields to catch programming errors */
+	res->attDescs = NULL;
+	res->tuples = NULL;
+	res->errFields = NULL;
+	/* res->curBlock was zeroed out earlier */
+
 	/* Free the PGresult structure itself */
 	free(res);
 }

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.184 2006/05/23 22:13:19 momjian Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.185 2006/05/28 17:23:29 alvherre Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -364,6 +364,12 @@ PQclear(PGresult *res)`
`364`	`364`	`if (res->tuples)`
`365`	`365`	`free(res->tuples);`
`366`	`366`
	`367`	`+ /* zero out the pointer fields to catch programming errors */`
	`368`	`+ res->attDescs = NULL;`
	`369`	`+ res->tuples = NULL;`
	`370`	`+ res->errFields = NULL;`
	`371`	`+ /* res->curBlock was zeroed out earlier */`
	`372`	`+`
`367`	`373`	`/* Free the PGresult structure itself */`
`368`	`374`	`free(res);`
`369`	`375`	`}`