Reword recent error messages: "should" -> "must"

Most were introduced in the 17 timeframe.  The ones in wparser_def.c are
very old.

I also changed "JSON path expression for column \"%s\" should return
single item without wrapper" to "JSON path expression for column \"%s\"
must return single item when no wrapper is requested" to avoid
ambiguity.

Backpatch to 17.

Crickets: https://postgr.es/m/202501131819.26ors7oouafu@alvherre.pgsql

src/backend/tsearch/wparser_def.c

@@ -2671,19 +2671,19 @@ prsd_headline(PG_FUNCTION_ARGS)
 		if (min_words >= max_words)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("MinWords should be less than MaxWords")));
+					 errmsg("%s must be less than %s", "MinWords", "MaxWords")));
 		if (min_words <= 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("MinWords should be positive")));
+					 errmsg("%s must be positive", "MinWords")));
 		if (shortword < 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("ShortWord should be >= 0")));
+					 errmsg("%s must be >= 0", "ShortWord")));
 		if (max_fragments < 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("MaxFragments should be >= 0")));
+					 errmsg("%s must be >= 0", "MaxFragments")));
 	}
 
 	/* Locate words and phrases matching the query */

src/backend/utils/adt/jsonpath_exec.c

@@ -3978,13 +3978,13 @@ JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper, bool *empty,
 		if (column_name)
 			ereport(ERROR,
 					(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
-					 errmsg("JSON path expression for column \"%s\" should return single item without wrapper",
+					 errmsg("JSON path expression for column \"%s\" must return single item when no wrapper is requested",
 							column_name),
 					 errhint("Use the WITH WRAPPER clause to wrap SQL/JSON items into an array.")));
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
-					 errmsg("JSON path expression in JSON_QUERY should return single item without wrapper"),
+					 errmsg("JSON path expression in JSON_QUERY must return single item when no wrapper is requested"),
 					 errhint("Use the WITH WRAPPER clause to wrap SQL/JSON items into an array.")));
 	}
 
@@ -4042,12 +4042,12 @@ JsonPathValue(Datum jb, JsonPath *jp, bool *empty, bool *error, List *vars,
 		if (column_name)
 			ereport(ERROR,
 					(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
-					 errmsg("JSON path expression for column \"%s\" should return single scalar item",
+					 errmsg("JSON path expression for column \"%s\" must return single scalar item",
 							column_name)));
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_MORE_THAN_ONE_SQL_JSON_ITEM),
-					 errmsg("JSON path expression in JSON_VALUE should return single scalar item")));
+					 errmsg("JSON path expression in JSON_VALUE must return single scalar item")));
 	}
 
 	res = JsonValueListHead(&found);
@@ -4066,12 +4066,12 @@ JsonPathValue(Datum jb, JsonPath *jp, bool *empty, bool *error, List *vars,
 		if (column_name)
 			ereport(ERROR,
 					(errcode(ERRCODE_SQL_JSON_SCALAR_REQUIRED),
-					 errmsg("JSON path expression for column \"%s\" should return single scalar item",
+					 errmsg("JSON path expression for column \"%s\" must return single scalar item",
 							column_name)));
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_SQL_JSON_SCALAR_REQUIRED),
-					 errmsg("JSON path expression in JSON_VALUE should return single scalar item")));
+					 errmsg("JSON path expression in JSON_VALUE must return single scalar item")));
 	}
 
 	if (res->type == jbvNull)

src/test/regress/expected/sqljson_jsontable.out

@@ -709,7 +709,7 @@ LINE 1: SELECT * FROM JSON_TABLE(jsonb '{"a": 123}', '$' || '.' || '...
                                                      ^
 -- JsonPathQuery() error message mentioning column name
 SELECT * FROM JSON_TABLE('{"a": [{"b": "1"}, {"b": "2"}]}', '$' COLUMNS (b json path '$.a[*].b' ERROR ON ERROR));
-ERROR:  JSON path expression for column "b" should return single item without wrapper
+ERROR:  JSON path expression for column "b" must return single item when no wrapper is requested
 HINT:  Use the WITH WRAPPER clause to wrap SQL/JSON items into an array.
 -- JSON_TABLE: nested paths
 -- Duplicate path names

src/test/regress/expected/sqljson_queryfuncs.out

@@ -344,7 +344,7 @@ SELECT JSON_VALUE(jsonb '[]', '$');
 (1 row)
 
 SELECT JSON_VALUE(jsonb '[]', '$' ERROR ON ERROR);
-ERROR:  JSON path expression in JSON_VALUE should return single scalar item
+ERROR:  JSON path expression in JSON_VALUE must return single scalar item
 SELECT JSON_VALUE(jsonb '{}', '$');
  json_value 
 ------------
@@ -352,7 +352,7 @@ SELECT JSON_VALUE(jsonb '{}', '$');
 (1 row)
 
 SELECT JSON_VALUE(jsonb '{}', '$' ERROR ON ERROR);
-ERROR:  JSON path expression in JSON_VALUE should return single scalar item
+ERROR:  JSON path expression in JSON_VALUE must return single scalar item
 SELECT JSON_VALUE(jsonb '1', '$.a');
  json_value 
 ------------
@@ -408,7 +408,7 @@ SELECT JSON_VALUE(jsonb '1', 'lax $.a' DEFAULT '2' ON EMPTY DEFAULT '3' ON ERROR
 SELECT JSON_VALUE(jsonb '1', 'lax $.a' ERROR ON EMPTY DEFAULT '3' ON ERROR);
 ERROR:  no SQL/JSON item found for specified path
 SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
-ERROR:  JSON path expression in JSON_VALUE should return single scalar item
+ERROR:  JSON path expression in JSON_VALUE must return single scalar item
 SELECT JSON_VALUE(jsonb '[1,2]', '$[*]' DEFAULT '0' ON ERROR);
  json_value 
 ------------
@@ -806,7 +806,7 @@ SELECT JSON_QUERY(jsonb '[]', '$[*]' ERROR ON ERROR);	-- NULL ON EMPTY
 (1 row)
 
 SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' ERROR ON ERROR);
-ERROR:  JSON path expression in JSON_QUERY should return single item without wrapper
+ERROR:  JSON path expression in JSON_QUERY must return single item when no wrapper is requested
 HINT:  Use the WITH WRAPPER clause to wrap SQL/JSON items into an array.
 SELECT JSON_QUERY(jsonb '[1,2]', '$[*]' DEFAULT '"empty"' ON ERROR);
  json_query