Fix connection string handling in src/bin/scripts/ programs.

When told to process all databases, clusterdb, reindexdb, and vacuumdb
would reconnect by replacing their --maintenance-db parameter with the
name of the target database.  If that parameter is a connstring (which
has been allowed for a long time, though we failed to document that
before this patch), we'd lose any other options it might specify, for
example SSL or GSS parameters, possibly resulting in failure to connect.
Thus, this is the same bug as commit a45bc8a4f fixed in pg_dump and
pg_restore.  We can fix it in the same way, by using libpq's rules for
handling multiple "dbname" parameters to add the target database name
separately.  I chose to apply the same refactoring approach as in that
patch, with a struct to handle the command line parameters that need to
be passed through to connectDatabase.  (Maybe someday we can unify the
very similar functions here and in pg_dump/pg_restore.)

Per Peter Eisentraut's comments on bug #16604.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/16604-933f4b8791227b15@postgresql.org

1 files changed, 19 insertions, 7 deletions

diff --git a/src/bin/scripts/common.h b/src/bin/scripts/common.h
index 30a39a62475..3c648da8528 100644
--- a/src/bin/scripts/common.h
+++ b/src/bin/scripts/common.h
@@ -23,20 +23,32 @@ enum trivalue
 
 extern bool CancelRequested;
 
+/* Parameters needed by connectDatabase/connectMaintenanceDatabase */
+typedef struct _connParams
+{
+	/* These fields record the actual command line parameters */
+	const char *dbname;			/* this may be a connstring! */
+	const char *pghost;
+	const char *pgport;
+	const char *pguser;
+	enum trivalue prompt_password;
+	/* If not NULL, this overrides the dbname obtained from command line */
+	/* (but *only* the DB name, not anything else in the connstring) */
+	const char *override_dbname;
+} ConnParams;
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
 						 const char *fixed_progname,
 						 help_handler hlp);
 
-extern PGconn *connectDatabase(const char *dbname, const char *pghost,
-				const char *pgport, const char *pguser,
-				enum trivalue prompt_password, const char *progname,
-				bool echo, bool fail_ok, bool allow_password_reuse);
+extern PGconn *connectDatabase(const ConnParams *cparams,
+							   const char *progname,
+							   bool echo, bool fail_ok,
+							   bool allow_password_reuse);
 
-extern PGconn *connectMaintenanceDatabase(const char *maintenance_db,
-						   const char *pghost, const char *pgport,
-						   const char *pguser, enum trivalue prompt_password,
+extern PGconn *connectMaintenanceDatabase(ConnParams *cparams,
 						   const char *progname, bool echo);
 
 extern PGresult *executeQuery(PGconn *conn, const char *query,