Remove support for upgrading extensions from "unpackaged" state.

Andres Freund pointed out that allowing non-superusers to run
"CREATE EXTENSION ... FROM unpackaged" has security risks, since
the unpackaged-to-1.0 scripts don't try to verify that the existing
objects they're modifying are what they expect.  Just attaching such
objects to an extension doesn't seem too dangerous, but some of them
do more than that.

We could have resolved this, perhaps, by still requiring superuser
privilege to use the FROM option.  However, it's fair to ask just what
we're accomplishing by continuing to lug the unpackaged-to-1.0 scripts
forward.  None of them have received any real testing since 9.1 days,
so they may not even work anymore (even assuming that one could still
load the previous "loose" object definitions into a v13 database).
And an installation that's trying to go from pre-9.1 to v13 or later
in one jump is going to have worse compatibility problems than whether
there's a trivial way to convert their contrib modules into extension
style.

Hence, let's just drop both those scripts and the core-code support
for "CREATE EXTENSION ... FROM".

Discussion: https://postgr.es/m/20200213233015.r6rnubcvl4egdh5r@alap3.anarazel.de

src/backend/commands/extension.c

@@ -1357,7 +1357,6 @@ static ObjectAddress
 CreateExtensionInternal(char *extensionName,
 						char *schemaName,
 						const char *versionName,
-						const char *oldVersionName,
 						bool cascade,
 						List *parents,
 						bool is_create)
@@ -1367,6 +1366,8 @@ CreateExtensionInternal(char *extensionName,
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
+	char	   *filename;
+	struct stat fst;
 	List	   *updateVersions;
 	List	   *requiredExtensions;
 	List	   *requiredSchemas;
@@ -1401,56 +1402,6 @@ CreateExtensionInternal(char *extensionName,
 	 * does what is needed, we try to find a sequence of update scripts that
 	 * will get us there.
 	 */
-	if (oldVersionName)
-	{
-		/*
-		 * "FROM old_version" was specified, indicating that we're trying to
-		 * update from some unpackaged version of the extension.  Locate a
-		 * series of update scripts that will do it.
-		 */
-		check_valid_version_name(oldVersionName);
-
-		if (strcmp(oldVersionName, versionName) == 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("FROM version must be different from installation target version \"%s\"",
-							versionName)));
-
-		updateVersions = identify_update_path(pcontrol,
-											  oldVersionName,
-											  versionName);
-
-		if (list_length(updateVersions) == 1)
-		{
-			/*
-			 * Simple case where there's just one update script to run. We
-			 * will not need any follow-on update steps.
-			 */
-			Assert(strcmp((char *) linitial(updateVersions), versionName) == 0);
-			updateVersions = NIL;
-		}
-		else
-		{
-			/*
-			 * Multi-step sequence.  We treat this as installing the version
-			 * that is the target of the first script, followed by successive
-			 * updates to the later versions.
-			 */
-			versionName = (char *) linitial(updateVersions);
-			updateVersions = list_delete_first(updateVersions);
-		}
-	}
-	else
-	{
-		/*
-		 * No FROM, so we're installing from scratch.  If there is an install
-		 * script for the desired version, we only need to run that one.
-		 */
-		char	   *filename;
-		struct stat fst;
-
-		oldVersionName = NULL;
-
 		filename = get_extension_script_filename(pcontrol, NULL, versionName);
 		if (stat(filename, &fst) == 0)
 		{
@@ -1484,7 +1435,6 @@ CreateExtensionInternal(char *extensionName,
 			/* Otherwise, install best starting point and then upgrade */
 			versionName = evi_start->name;
 		}
-	}
 
 	/*
 	 * Fetch control parameters for installation target version
@@ -1624,7 +1574,7 @@ CreateExtensionInternal(char *extensionName,
 	 * Execute the installation script file
 	 */
 	execute_extension_script(extensionOid, control,
-							 oldVersionName, versionName,
+							 NULL, versionName,
 							 requiredSchemas,
 							 schemaName, schemaOid);
 
@@ -1691,7 +1641,6 @@ get_required_extension(char *reqExtensionName,
 			addr = CreateExtensionInternal(reqExtensionName,
 										   origSchemaName,
 										   NULL,
-										   NULL,
 										   cascade,
 										   cascade_parents,
 										   is_create);
@@ -1719,11 +1668,9 @@ CreateExtension(ParseState *pstate, CreateExtensionStmt *stmt)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
-	DefElem    *d_old_version = NULL;
 	DefElem    *d_cascade = NULL;
 	char	   *schemaName = NULL;
 	char	   *versionName = NULL;
-	char	   *oldVersionName = NULL;
 	bool		cascade = false;
 	ListCell   *lc;
 
@@ -1787,16 +1734,6 @@ CreateExtension(ParseState *pstate, CreateExtensionStmt *stmt)
 			d_new_version = defel;
 			versionName = defGetString(d_new_version);
 		}
-		else if (strcmp(defel->defname, "old_version") == 0)
-		{
-			if (d_old_version)
-				ereport(ERROR,
-						(errcode(ERRCODE_SYNTAX_ERROR),
-						 errmsg("conflicting or redundant options"),
-						 parser_errposition(pstate, defel->location)));
-			d_old_version = defel;
-			oldVersionName = defGetString(d_old_version);
-		}
 		else if (strcmp(defel->defname, "cascade") == 0)
 		{
 			if (d_cascade)
@@ -1815,7 +1752,6 @@ CreateExtension(ParseState *pstate, CreateExtensionStmt *stmt)
 	return CreateExtensionInternal(stmt->extname,
 								   schemaName,
 								   versionName,
-								   oldVersionName,
 								   cascade,
 								   NIL,
 								   true);

src/backend/parser/gram.y

@@ -4460,7 +4460,7 @@ DropTableSpaceStmt: DROP TABLESPACE name
  *
  *		QUERY:
  *             CREATE EXTENSION extension
- *             [ WITH ] [ SCHEMA schema ] [ VERSION version ] [ FROM oldversion ]
+ *             [ WITH ] [ SCHEMA schema ] [ VERSION version ]
  *
  *****************************************************************************/
 
@@ -4500,7 +4500,10 @@ create_extension_opt_item:
 				}
 			| FROM NonReservedWord_or_Sconst
 				{
-					$$ = makeDefElem("old_version", (Node *)makeString($2), @1);
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("CREATE EXTENSION ... FROM is no longer supported"),
+							 parser_errposition(@1)));
 				}
 			| CASCADE
 				{

src/pl/plperl/GNUmakefile

@@ -27,8 +27,8 @@ NAME = plperl
 
 OBJS = plperl.o SPI.o Util.o $(WIN32RES)
 
-DATA = plperl.control plperl--1.0.sql plperl--unpackaged--1.0.sql \
-       plperlu.control plperlu--1.0.sql plperlu--unpackaged--1.0.sql
+DATA = plperl.control plperl--1.0.sql \
+       plperlu.control plperlu--1.0.sql
 
 PERLCHUNKS = plc_perlboot.pl plc_trusted.pl
 

src/pl/plperl/plperl--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plperl/plperl--unpackaged--1.0.sql */
-
-ALTER EXTENSION plperl ADD LANGUAGE plperl;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plperl ADD FUNCTION plperl_call_handler();
-ALTER EXTENSION plperl ADD FUNCTION plperl_inline_handler(internal);
-ALTER EXTENSION plperl ADD FUNCTION plperl_validator(oid);

src/pl/plperl/plperlu--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plperl/plperlu--unpackaged--1.0.sql */
-
-ALTER EXTENSION plperlu ADD LANGUAGE plperlu;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plperlu ADD FUNCTION plperlu_call_handler();
-ALTER EXTENSION plperlu ADD FUNCTION plperlu_inline_handler(internal);
-ALTER EXTENSION plperlu ADD FUNCTION plperlu_validator(oid);

src/pl/plpgsql/src/Makefile

@@ -28,7 +28,7 @@ OBJS = \
 	pl_handler.o \
 	pl_scanner.o
 
-DATA = plpgsql.control plpgsql--1.0.sql plpgsql--unpackaged--1.0.sql
+DATA = plpgsql.control plpgsql--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB)
 

src/pl/plpgsql/src/plpgsql--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plpgsql/src/plpgsql--unpackaged--1.0.sql */
-
-ALTER EXTENSION plpgsql ADD LANGUAGE plpgsql;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_call_handler();
-ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_inline_handler(internal);
-ALTER EXTENSION plpgsql ADD FUNCTION plpgsql_validator(oid);

src/pl/plpython/Makefile

@@ -34,9 +34,9 @@ OBJS = \
 	plpy_typeio.o \
 	plpy_util.o
 
-DATA = $(NAME)u.control $(NAME)u--1.0.sql $(NAME)u--unpackaged--1.0.sql
+DATA = $(NAME)u.control $(NAME)u--1.0.sql
 ifeq ($(python_majorversion),2)
-DATA += plpythonu.control plpythonu--1.0.sql plpythonu--unpackaged--1.0.sql
+DATA += plpythonu.control plpythonu--1.0.sql
 endif
 
 # header files to install - it's not clear which of these might be needed

src/pl/plpython/plpython2u--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plpython/plpython2u--unpackaged--1.0.sql */
-
-ALTER EXTENSION plpython2u ADD LANGUAGE plpython2u;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plpython2u ADD FUNCTION plpython2_call_handler();
-ALTER EXTENSION plpython2u ADD FUNCTION plpython2_inline_handler(internal);
-ALTER EXTENSION plpython2u ADD FUNCTION plpython2_validator(oid);

src/pl/plpython/plpython3u--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plpython/plpython3u--unpackaged--1.0.sql */
-
-ALTER EXTENSION plpython3u ADD LANGUAGE plpython3u;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plpython3u ADD FUNCTION plpython3_call_handler();
-ALTER EXTENSION plpython3u ADD FUNCTION plpython3_inline_handler(internal);
-ALTER EXTENSION plpython3u ADD FUNCTION plpython3_validator(oid);

src/pl/plpython/plpythonu--unpackaged--1.0.sql

@@ -1,7 +0,0 @@
-/* src/pl/plpython/plpythonu--unpackaged--1.0.sql */
-
-ALTER EXTENSION plpythonu ADD LANGUAGE plpythonu;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION plpythonu ADD FUNCTION plpython_call_handler();
-ALTER EXTENSION plpythonu ADD FUNCTION plpython_inline_handler(internal);
-ALTER EXTENSION plpythonu ADD FUNCTION plpython_validator(oid);

src/pl/tcl/Makefile

@@ -26,8 +26,8 @@ OBJS = \
 	$(WIN32RES) \
 	pltcl.o
 
-DATA = pltcl.control pltcl--1.0.sql pltcl--unpackaged--1.0.sql \
-       pltclu.control pltclu--1.0.sql pltclu--unpackaged--1.0.sql
+DATA = pltcl.control pltcl--1.0.sql \
+       pltclu.control pltclu--1.0.sql
 
 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=pltcl
 REGRESS = pltcl_setup pltcl_queries pltcl_trigger pltcl_call pltcl_start_proc pltcl_subxact pltcl_unicode pltcl_transaction

src/pl/tcl/pltcl--unpackaged--1.0.sql

@@ -1,5 +0,0 @@
-/* src/pl/tcl/pltcl--unpackaged--1.0.sql */
-
-ALTER EXTENSION pltcl ADD LANGUAGE pltcl;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION pltcl ADD FUNCTION pltcl_call_handler();

src/pl/tcl/pltclu--unpackaged--1.0.sql

@@ -1,5 +0,0 @@
-/* src/pl/tcl/pltclu--unpackaged--1.0.sql */
-
-ALTER EXTENSION pltclu ADD LANGUAGE pltclu;
--- ALTER ADD LANGUAGE doesn't pick up the support functions, so we have to.
-ALTER EXTENSION pltclu ADD FUNCTION pltclu_call_handler();

src/test/modules/test_parser/Makefile

@@ -7,7 +7,7 @@ OBJS = \
 PGFILEDESC = "test_parser - example of a custom parser for full-text search"
 
 EXTENSION = test_parser
-DATA = test_parser--1.0.sql test_parser--unpackaged--1.0.sql
+DATA = test_parser--1.0.sql
 
 REGRESS = test_parser
 

src/test/modules/test_parser/test_parser--unpackaged--1.0.sql

@@ -1,10 +0,0 @@
-/* src/test/modules/test_parser/test_parser--unpackaged--1.0.sql */
-
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "CREATE EXTENSION test_parser FROM unpackaged" to load this file. \quit
-
-ALTER EXTENSION test_parser ADD function testprs_start(internal,integer);
-ALTER EXTENSION test_parser ADD function testprs_getlexeme(internal,internal,internal);
-ALTER EXTENSION test_parser ADD function testprs_end(internal);
-ALTER EXTENSION test_parser ADD function testprs_lextype(internal);
-ALTER EXTENSION test_parser ADD text search parser testparser;