Fix conversion of domains to JSON in 9.3 and 9.2.

tglsfdc · tglsfdc · commit 15026ab97950 · 2014-08-09T18:40:38.000-04:00
In commit 0ca6bda, I rewrote the json.c code that decided how to convert SQL data types into JSON values, so that it no longer relied on typcategory which is a pretty untrustworthy guide to the output format of user-defined datatypes. However, I overlooked the fact that CREATE DOMAIN inherits typcategory from the base type, so that the old coding did have the desirable property of treating domains like their base types --- but only in some cases, because not all its decisions turned on typcategory. The version of the patch that went into 9.4 and up did a getBaseType() call to ensure that domains were always treated like their base types, but I omitted that from the older branches, because it would result in a behavioral change for domains over json or hstore; a change that's arguably a bug fix, but nonetheless a change that users had not asked for. What I overlooked was that this meant that domains over numerics and boolean were no longer treated like their base types, and that we *did* get a complaint about, ie bug #11103 from David Grelaud. So let's do the getBaseType() call in the older branches as well, to restore their previous behavior in these cases. That means 9.2 and 9.3 will now make these decisions just like 9.4. We could probably kluge things to still ignore the domain's base type if it's json etc, but that seems a bit silly.
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
@@ -843,9 +843,8 @@ json_categorize_type(Oid typoid,
 {
 	bool		typisvarlena;
 
-	/*
-	 * We should look through domains here, but we'll wait till 9.4.
-	 */
+	/* Look through any domain */
+	typoid = getBaseType(typoid);
 
 	/* We'll usually need to return the type output function */
 	getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
