Support functions for index opclasses should be immutable.

Found by running opr_sanity on contrib modules.

contrib/ltree/ltree.sql.in

@@ -4,12 +4,12 @@ SET search_path = public;
 CREATE FUNCTION ltree_in(cstring)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE FUNCTION ltree_out(ltree)
 RETURNS cstring
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE TYPE ltree (
 	INTERNALLENGTH = -1,
@@ -23,37 +23,37 @@ CREATE TYPE ltree (
 CREATE FUNCTION ltree_cmp(ltree,ltree)
 RETURNS int4
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_lt(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_le(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_eq(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_ge(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_gt(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_ne(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 
 CREATE OPERATOR < (
@@ -123,112 +123,112 @@ CREATE OPERATOR <> (
 CREATE FUNCTION subltree(ltree,int4,int4)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION subpath(ltree,int4,int4)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION subpath(ltree,int4)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION index(ltree,ltree)
 RETURNS int4
 AS 'MODULE_PATHNAME', 'ltree_index'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION index(ltree,ltree,int4)
 RETURNS int4
 AS 'MODULE_PATHNAME', 'ltree_index'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION nlevel(ltree)
 RETURNS int4
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree2text(ltree)
 RETURNS text
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION text2ltree(text)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(_ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME','_lca'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree,ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree,ltree,ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lca(ltree,ltree,ltree,ltree,ltree,ltree,ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_isparent(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_risparent(ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_addltree(ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_addtext(ltree,text)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltree_textadd(text,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltreeparentsel(internal, oid, internal, integer)
 RETURNS float8
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR @> (
         LEFTARG = ltree,
@@ -301,12 +301,12 @@ CREATE OPERATOR CLASS ltree_ops
 CREATE FUNCTION lquery_in(cstring)
 RETURNS lquery
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE FUNCTION lquery_out(lquery)
 RETURNS cstring
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE TYPE lquery (
 	INTERNALLENGTH = -1,
@@ -318,12 +318,12 @@ CREATE TYPE lquery (
 CREATE FUNCTION ltq_regex(ltree,lquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltq_rregex(lquery,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ~ (
         LEFTARG = ltree,
@@ -365,12 +365,12 @@ CREATE OPERATOR ^~ (
 CREATE FUNCTION lt_q_regex(ltree,_lquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION lt_q_rregex(_lquery,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ? (
         LEFTARG = ltree,
@@ -412,12 +412,12 @@ CREATE OPERATOR ^? (
 CREATE FUNCTION ltxtq_in(cstring)
 RETURNS ltxtquery
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE FUNCTION ltxtq_out(ltxtquery)
 RETURNS cstring
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
 
 CREATE TYPE ltxtquery (
 	INTERNALLENGTH = -1,
@@ -431,12 +431,12 @@ CREATE TYPE ltxtquery (
 CREATE FUNCTION ltxtq_exec(ltree, ltxtquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION ltxtq_rexec(ltxtquery, ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR @ (
         LEFTARG = ltree,
@@ -479,12 +479,12 @@ CREATE OPERATOR ^@ (
 CREATE FUNCTION ltree_gist_in(cstring)
 RETURNS ltree_gist
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
   
 CREATE FUNCTION ltree_gist_out(ltree_gist)
 RETURNS cstring
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C STRICT;
   
 CREATE TYPE ltree_gist (
 	internallength = -1,
@@ -495,25 +495,25 @@ CREATE TYPE ltree_gist (
 
 
 CREATE FUNCTION ltree_consistent(internal,internal,int2)
-RETURNS bool as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS bool as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION ltree_compress(internal)
-RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION ltree_decompress(internal)
-RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION ltree_penalty(internal,internal,internal)
-RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C RETURNS NULL ON NULL INPUT;
+RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT;
 
 CREATE FUNCTION ltree_picksplit(internal, internal)
-RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION ltree_union(internal, internal)
-RETURNS int4 as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS int4 as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION ltree_same(internal, internal, internal)
-RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C;
+RETURNS internal as 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE;
 
 CREATE OPERATOR CLASS gist_ltree_ops
     DEFAULT FOR TYPE ltree USING gist AS
@@ -545,52 +545,52 @@ CREATE OPERATOR CLASS gist_ltree_ops
 CREATE FUNCTION _ltree_isparent(_ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltree_r_isparent(ltree,_ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltree_risparent(_ltree,ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltree_r_risparent(ltree,_ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltq_regex(_ltree,lquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltq_rregex(lquery,_ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _lt_q_regex(_ltree,_lquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _lt_q_rregex(_lquery,_ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltxtq_exec(_ltree, ltxtquery)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE FUNCTION _ltxtq_rexec(ltxtquery, _ltree)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR @> (
         LEFTARG = _ltree,
@@ -778,7 +778,7 @@ CREATE OPERATOR ^@ (
 CREATE FUNCTION _ltree_extract_isparent(_ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ?@> (
         LEFTARG = _ltree,
@@ -789,7 +789,7 @@ CREATE OPERATOR ?@> (
 CREATE FUNCTION _ltree_extract_risparent(_ltree,ltree)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ?<@ (
         LEFTARG = _ltree,
@@ -800,7 +800,7 @@ CREATE OPERATOR ?<@ (
 CREATE FUNCTION _ltq_extract_regex(_ltree,lquery)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ?~ (
         LEFTARG = _ltree,
@@ -811,7 +811,7 @@ CREATE OPERATOR ?~ (
 CREATE FUNCTION _ltxtq_extract_exec(_ltree,ltxtquery)
 RETURNS ltree
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT IMMUTABLE;
+LANGUAGE C STRICT IMMUTABLE;
 
 CREATE OPERATOR ?@ (
         LEFTARG = _ltree,
@@ -823,32 +823,32 @@ CREATE OPERATOR ?@ (
 CREATE FUNCTION _ltree_consistent(internal,internal,int2)
 RETURNS bool
 AS 'MODULE_PATHNAME'
-LANGUAGE C;
+LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION _ltree_compress(internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'
-LANGUAGE C;
+LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION _ltree_penalty(internal,internal,internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'
-LANGUAGE C RETURNS NULL ON NULL INPUT;
+LANGUAGE C IMMUTABLE STRICT;
 
 CREATE FUNCTION _ltree_picksplit(internal, internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'
-LANGUAGE C;
+LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION _ltree_union(internal, internal)
 RETURNS int4
 AS 'MODULE_PATHNAME'
-LANGUAGE C;
+LANGUAGE C IMMUTABLE;
 
 CREATE FUNCTION _ltree_same(internal, internal, internal)
 RETURNS internal
 AS 'MODULE_PATHNAME'
-LANGUAGE C;
+LANGUAGE C IMMUTABLE;
 
 CREATE OPERATOR CLASS gist__ltree_ops
     DEFAULT FOR TYPE _ltree USING gist AS