Rename 'cmd' to 'cmd_name' in CreatePolicyStmt

To avoid confusion, rename CreatePolicyStmt's 'cmd' to 'cmd_name',
parse_policy_command's 'cmd' to 'polcmd', and AlterPolicy's 'cmd_datum'
to 'polcmd_datum', per discussion with Noah and as a follow-up to his
correction of copynodes/equalnodes handling of the CreatePolicyStmt
'cmd' field.

Back-patch to 9.5 where the CreatePolicyStmt was introduced, as we
are still only in alpha.

src/backend/commands/policy.c

@@ -108,25 +108,25 @@ RangeVarCallbackForPolicy(const RangeVar *rv, Oid relid, Oid oldrelid,
 static char
 parse_policy_command(const char *cmd_name)
 {
-	char		cmd;
+	char		polcmd;
 
 	if (!cmd_name)
 		elog(ERROR, "unrecognized policy command");
 
 	if (strcmp(cmd_name, "all") == 0)
-		cmd = '*';
+		polcmd = '*';
 	else if (strcmp(cmd_name, "select") == 0)
-		cmd = ACL_SELECT_CHR;
+		polcmd = ACL_SELECT_CHR;
 	else if (strcmp(cmd_name, "insert") == 0)
-		cmd = ACL_INSERT_CHR;
+		polcmd = ACL_INSERT_CHR;
 	else if (strcmp(cmd_name, "update") == 0)
-		cmd = ACL_UPDATE_CHR;
+		polcmd = ACL_UPDATE_CHR;
 	else if (strcmp(cmd_name, "delete") == 0)
-		cmd = ACL_DELETE_CHR;
+		polcmd = ACL_DELETE_CHR;
 	else
 		elog(ERROR, "unrecognized policy command");
 
-	return cmd;
+	return polcmd;
 }
 
 /*
@@ -480,7 +480,7 @@ CreatePolicy(CreatePolicyStmt *stmt)
 	int			i;
 
 	/* Parse command */
-	polcmd = parse_policy_command(stmt->cmd);
+	polcmd = parse_policy_command(stmt->cmd_name);
 
 	/*
 	 * If the command is SELECT or DELETE then WITH CHECK should be NULL.
@@ -674,7 +674,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
 	bool		replaces[Natts_pg_policy];
 	ObjectAddress target;
 	ObjectAddress myself;
-	Datum		cmd_datum;
+	Datum		polcmd_datum;
 	char		polcmd;
 	bool		polcmd_isnull;
 	int			i;
@@ -775,11 +775,11 @@ AlterPolicy(AlterPolicyStmt *stmt)
 						RelationGetRelationName(target_table))));
 
 	/* Get policy command */
-	cmd_datum = heap_getattr(policy_tuple, Anum_pg_policy_polcmd,
+	polcmd_datum = heap_getattr(policy_tuple, Anum_pg_policy_polcmd,
 							 RelationGetDescr(pg_policy_rel),
 							 &polcmd_isnull);
 	Assert(!polcmd_isnull);
-	polcmd = DatumGetChar(cmd_datum);
+	polcmd = DatumGetChar(polcmd_datum);
 
 	/*
 	 * If the command is SELECT or DELETE then WITH CHECK should be NULL.

src/backend/nodes/copyfuncs.c

@@ -4083,7 +4083,7 @@ _copyCreatePolicyStmt(const CreatePolicyStmt *from)
 
 	COPY_STRING_FIELD(policy_name);
 	COPY_NODE_FIELD(table);
-	COPY_STRING_FIELD(cmd);
+	COPY_STRING_FIELD(cmd_name);
 	COPY_NODE_FIELD(roles);
 	COPY_NODE_FIELD(qual);
 	COPY_NODE_FIELD(with_check);

src/backend/nodes/equalfuncs.c

@@ -2074,7 +2074,7 @@ _equalCreatePolicyStmt(const CreatePolicyStmt *a, const CreatePolicyStmt *b)
 {
 	COMPARE_STRING_FIELD(policy_name);
 	COMPARE_NODE_FIELD(table);
-	COMPARE_STRING_FIELD(cmd);
+	COMPARE_STRING_FIELD(cmd_name);
 	COMPARE_NODE_FIELD(roles);
 	COMPARE_NODE_FIELD(qual);
 	COMPARE_NODE_FIELD(with_check);

src/backend/parser/gram.y

@@ -4613,7 +4613,7 @@ CreatePolicyStmt:
 					CreatePolicyStmt *n = makeNode(CreatePolicyStmt);
 					n->policy_name = $3;
 					n->table = $5;
-					n->cmd = $6;
+					n->cmd_name = $6;
 					n->roles = $7;
 					n->qual = $8;
 					n->with_check = $9;

src/include/nodes/parsenodes.h

@@ -2039,7 +2039,7 @@ typedef struct CreatePolicyStmt
 	NodeTag		type;
 	char	   *policy_name;	/* Policy's name */
 	RangeVar   *table;			/* the table name the policy applies to */
-	char	   *cmd;			/* the command name the policy applies to */
+	char	   *cmd_name;		/* the command name the policy applies to */
 	List	   *roles;			/* the roles associated with the policy */
 	Node	   *qual;			/* the policy's condition */
 	Node	   *with_check;		/* the policy's WITH CHECK condition. */