Fix tab-completion for COPY and \copy options.

Commit c273d9d8ce reworked tab-completion of COPY and \copy in psql
and added support for completing options within WITH clauses. However,
the same COPY options were suggested for both COPY TO and COPY FROM
commands, even though some options are only valid for one or the
other.

This commit separates the COPY options for COPY FROM and COPY TO
commands to provide more accurate auto-completion suggestions.

Back-patch to v14 where tab-completion for COPY and \copy options
within WITH clauses was first supported.

Author: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Yugo Nagata <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/079e7a2c801f252ae8d522b772790ed7@oss.nttdata.com
Backpatch-through: 14

src/bin/psql/tab-complete.c

@@ -1164,6 +1164,18 @@ Alter_procedure_options, "COST", "IMMUTABLE", "LEAKPROOF", "NOT LEAKPROOF", \
 Alter_routine_options, "CALLED ON NULL INPUT", "RETURNS NULL ON NULL INPUT", \
 "STRICT", "SUPPORT"
 
+/* COPY options shared between FROM and TO */
+#define Copy_common_options \
+"DELIMITER", "ENCODING", "ESCAPE", "FORMAT", "HEADER", "NULL", "QUOTE"
+
+/* COPY FROM options */
+#define Copy_from_options \
+Copy_common_options, "DEFAULT", "FORCE_NOT_NULL", "FORCE_NULL", "FREEZE"
+
+/* COPY TO options */
+#define Copy_to_options \
+Copy_common_options, "FORCE_QUOTE"
+
 /*
  * These object types were introduced later than our support cutoff of
  * server version 9.2.  We use the VersionedQuery infrastructure so that
@@ -2854,11 +2866,13 @@ psql_completion(const char *text, int start, int end)
 	else if (Matches("COPY|\\copy", MatchAny, "FROM", MatchAny))
 		COMPLETE_WITH("WITH (", "WHERE");
 
-	/* Complete COPY <sth> FROM|TO filename WITH ( */
-	else if (Matches("COPY|\\copy", MatchAny, "FROM|TO", MatchAny, "WITH", "("))
-		COMPLETE_WITH("FORMAT", "FREEZE", "DELIMITER", "NULL",
-					  "HEADER", "QUOTE", "ESCAPE", "FORCE_QUOTE",
-					  "FORCE_NOT_NULL", "FORCE_NULL", "ENCODING", "DEFAULT");
+	/* Complete COPY <sth> FROM filename WITH ( */
+	else if (Matches("COPY|\\copy", MatchAny, "FROM", MatchAny, "WITH", "("))
+		COMPLETE_WITH(Copy_from_options);
+
+	/* Complete COPY <sth> TO filename WITH ( */
+	else if (Matches("COPY|\\copy", MatchAny, "TO", MatchAny, "WITH", "("))
+		COMPLETE_WITH(Copy_to_options);
 
 	/* Complete COPY <sth> FROM|TO filename WITH (FORMAT */
 	else if (Matches("COPY|\\copy", MatchAny, "FROM|TO", MatchAny, "WITH", "(", "FORMAT"))