Change pg_seclabel.provider and pg_shseclabel.provider to type "name".

These were "text", but that's a bad idea because it has collation-dependent
ordering.  No index in template0 should have collation-dependent ordering,
especially not indexes on shared catalogs.  There was general agreement
that provider names don't need to be longer than other identifiers, so we
can fix this at a small waste of table space by changing from text to name.

There's no way to fix the problem in the back branches, but we can hope
that security labels don't yet have widespread-enough usage to make it
urgent to fix.

There needs to be a regression sanity test to prevent us from making this
same mistake again; but before putting that in, we'll need to get rid of
similar brain fade in the recently-added pg_replication_origin catalog.

Note: for lack of a suitable testing environment, I've not really exercised
this change.  I trust the buildfarm will show up any mistakes.

doc/src/sgml/catalogs.sgml

@@ -5648,7 +5648,7 @@
 
      <row>
       <entry><structfield>provider</structfield></entry>
-      <entry><type>text</type></entry>
+      <entry><type>name</type></entry>
       <entry></entry>
       <entry>The label provider associated with this label.</entry>
      </row>
@@ -5937,7 +5937,7 @@
      </row>
      <row>
       <entry><structfield>provider</structfield></entry>
-      <entry><type>text</type></entry>
+      <entry><type>name</type></entry>
       <entry></entry>
       <entry>The label provider associated with this label.</entry>
      </row>
@@ -9025,7 +9025,7 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
      </row>
      <row>
       <entry><structfield>provider</structfield></entry>
-      <entry><type>text</type></entry>
+      <entry><type>name</type></entry>
       <entry><literal><link linkend="catalog-pg-seclabel"><structname>pg_seclabel</structname></link>.provider</literal></entry>
       <entry>The label provider associated with this label.</entry>
      </row>

src/backend/commands/seclabel.c

@@ -163,8 +163,8 @@ GetSharedSecurityLabel(const ObjectAddress *object, const char *provider)
 				ObjectIdGetDatum(object->classId));
 	ScanKeyInit(&keys[2],
 				Anum_pg_shseclabel_provider,
-				BTEqualStrategyNumber, F_TEXTEQ,
-				CStringGetTextDatum(provider));
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(provider));
 
 	pg_shseclabel = heap_open(SharedSecLabelRelationId, AccessShareLock);
 
@@ -220,8 +220,8 @@ GetSecurityLabel(const ObjectAddress *object, const char *provider)
 				Int32GetDatum(object->objectSubId));
 	ScanKeyInit(&keys[3],
 				Anum_pg_seclabel_provider,
-				BTEqualStrategyNumber, F_TEXTEQ,
-				CStringGetTextDatum(provider));
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(provider));
 
 	pg_seclabel = heap_open(SecLabelRelationId, AccessShareLock);
 
@@ -256,6 +256,7 @@ SetSharedSecurityLabel(const ObjectAddress *object,
 	SysScanDesc scan;
 	HeapTuple	oldtup;
 	HeapTuple	newtup = NULL;
+	NameData	providername;
 	Datum		values[Natts_pg_shseclabel];
 	bool		nulls[Natts_pg_shseclabel];
 	bool		replaces[Natts_pg_shseclabel];
@@ -265,7 +266,8 @@ SetSharedSecurityLabel(const ObjectAddress *object,
 	memset(replaces, false, sizeof(replaces));
 	values[Anum_pg_shseclabel_objoid - 1] = ObjectIdGetDatum(object->objectId);
 	values[Anum_pg_shseclabel_classoid - 1] = ObjectIdGetDatum(object->classId);
-	values[Anum_pg_shseclabel_provider - 1] = CStringGetTextDatum(provider);
+	namestrcpy(&providername, provider);
+	values[Anum_pg_shseclabel_provider - 1] = NameGetDatum(&providername);
 	if (label != NULL)
 		values[Anum_pg_shseclabel_label - 1] = CStringGetTextDatum(label);
 
@@ -280,8 +282,8 @@ SetSharedSecurityLabel(const ObjectAddress *object,
 				ObjectIdGetDatum(object->classId));
 	ScanKeyInit(&keys[2],
 				Anum_pg_shseclabel_provider,
-				BTEqualStrategyNumber, F_TEXTEQ,
-				CStringGetTextDatum(provider));
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(provider));
 
 	pg_shseclabel = heap_open(SharedSecLabelRelationId, RowExclusiveLock);
 
@@ -335,6 +337,7 @@ SetSecurityLabel(const ObjectAddress *object,
 	SysScanDesc scan;
 	HeapTuple	oldtup;
 	HeapTuple	newtup = NULL;
+	NameData	providername;
 	Datum		values[Natts_pg_seclabel];
 	bool		nulls[Natts_pg_seclabel];
 	bool		replaces[Natts_pg_seclabel];
@@ -352,7 +355,8 @@ SetSecurityLabel(const ObjectAddress *object,
 	values[Anum_pg_seclabel_objoid - 1] = ObjectIdGetDatum(object->objectId);
 	values[Anum_pg_seclabel_classoid - 1] = ObjectIdGetDatum(object->classId);
 	values[Anum_pg_seclabel_objsubid - 1] = Int32GetDatum(object->objectSubId);
-	values[Anum_pg_seclabel_provider - 1] = CStringGetTextDatum(provider);
+	namestrcpy(&providername, provider);
+	values[Anum_pg_seclabel_provider - 1] = NameGetDatum(&providername);
 	if (label != NULL)
 		values[Anum_pg_seclabel_label - 1] = CStringGetTextDatum(label);
 
@@ -371,8 +375,8 @@ SetSecurityLabel(const ObjectAddress *object,
 				Int32GetDatum(object->objectSubId));
 	ScanKeyInit(&keys[3],
 				Anum_pg_seclabel_provider,
-				BTEqualStrategyNumber, F_TEXTEQ,
-				CStringGetTextDatum(provider));
+				BTEqualStrategyNumber, F_NAMEEQ,
+				CStringGetDatum(provider));
 
 	pg_seclabel = heap_open(SecLabelRelationId, RowExclusiveLock);
 

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201505153
+#define CATALOG_VERSION_NO	201505181
 
 #endif

src/include/catalog/indexing.h

@@ -290,10 +290,10 @@ DECLARE_UNIQUE_INDEX(pg_default_acl_oid_index, 828, on pg_default_acl using btre
 DECLARE_UNIQUE_INDEX(pg_db_role_setting_databaseid_rol_index, 2965, on pg_db_role_setting using btree(setdatabase oid_ops, setrole oid_ops));
 #define DbRoleSettingDatidRolidIndexId	2965
 
-DECLARE_UNIQUE_INDEX(pg_seclabel_object_index, 3597, on pg_seclabel using btree(objoid oid_ops, classoid oid_ops, objsubid int4_ops, provider text_ops));
+DECLARE_UNIQUE_INDEX(pg_seclabel_object_index, 3597, on pg_seclabel using btree(objoid oid_ops, classoid oid_ops, objsubid int4_ops, provider name_ops));
 #define SecLabelObjectIndexId				3597
 
-DECLARE_UNIQUE_INDEX(pg_shseclabel_object_index, 3593, on pg_shseclabel using btree(objoid oid_ops, classoid oid_ops, provider text_ops));
+DECLARE_UNIQUE_INDEX(pg_shseclabel_object_index, 3593, on pg_shseclabel using btree(objoid oid_ops, classoid oid_ops, provider name_ops));
 #define SharedSecLabelObjectIndexId			3593
 
 DECLARE_UNIQUE_INDEX(pg_extension_oid_index, 3080, on pg_extension using btree(oid oid_ops));

src/include/catalog/pg_seclabel.h

@@ -25,9 +25,9 @@ CATALOG(pg_seclabel,3596) BKI_WITHOUT_OIDS
 	Oid			objoid;			/* OID of the object itself */
 	Oid			classoid;		/* OID of table containing the object */
 	int32		objsubid;		/* column number, or 0 if not used */
+	NameData	provider;		/* name of label provider */
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
-	text		provider BKI_FORCE_NOT_NULL; /* name of label provider */
 	text		label BKI_FORCE_NOT_NULL; /* security label of the object */
 #endif
 } FormData_pg_seclabel;

src/include/catalog/pg_shseclabel.h

@@ -24,9 +24,9 @@ CATALOG(pg_shseclabel,3592) BKI_SHARED_RELATION BKI_WITHOUT_OIDS
 {
 	Oid			objoid;			/* OID of the shared object itself */
 	Oid			classoid;		/* OID of table containing the shared object */
+	NameData	provider;		/* name of label provider */
 
 #ifdef CATALOG_VARLEN			/* variable-length fields start here */
-	text		provider BKI_FORCE_NOT_NULL; /* name of label provider */
 	text		label BKI_FORCE_NOT_NULL; /* security label of the object */
 #endif
 } FormData_pg_shseclabel;