psql: Fix tab-completion after GRANT/REVOKE on LARGE OBJECT and FOREIGN SERVER.

Previously, when pressing Tab after GRANT or REVOKE ... ON LARGE OBJECT
or ON FOREIGN SERVER, TO or FROM was incorrectly suggested by psql's
tab-completion. This was not appropriate, as those clauses are not valid
at that point.

This commit fixes the issue by preventing TO and FROM from being offered
immediately after those specific GRANT/REVOKE statements.

Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20250408122857.b2b06dde4e6a08290af02336@sraoss.co.jp

diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 6872653c6c82800776e1f19cde19816f1d5d9c74..37524364290ce713124217c9c2457c449e21f275 100644 (file)
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4619,10 +4619,14 @@ match_previous_words(int pattern_id,
    else if (Matches("ALTER", "DEFAULT", "PRIVILEGES", MatchAnyN, "TO", MatchAny))
        COMPLETE_WITH("WITH GRANT OPTION");
    /* Complete "GRANT/REVOKE ... ON * *" with TO/FROM */
-   else if (Matches("GRANT", MatchAnyN, "ON", MatchAny, MatchAny))
-       COMPLETE_WITH("TO");
-   else if (Matches("REVOKE", MatchAnyN, "ON", MatchAny, MatchAny))
-       COMPLETE_WITH("FROM");
+   else if (Matches("GRANT|REVOKE", MatchAnyN, "ON", MatchAny, MatchAny) &&
+            !TailMatches("FOREIGN", "SERVER") && !TailMatches("LARGE", "OBJECT"))
+   {
+       if (Matches("GRANT", MatchAnyN, "ON", MatchAny, MatchAny))
+           COMPLETE_WITH("TO");
+       else
+           COMPLETE_WITH("FROM");
+   }
 
    /* Complete "GRANT/REVOKE * ON ALL * IN SCHEMA *" with TO/FROM */
    else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL", MatchAny, "IN", "SCHEMA", MatchAny) ||