Get rid of client-code dependencies on the exact text of the no-password

error message, by using PQconnectionUsedPassword() instead.  Someday
we might be able to localize that error message, but not until this
coding technique has disappeared everywhere.

src/bin/pg_ctl/pg_ctl.c

@@ -4,7 +4,7 @@
  *
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.81 2007/07/02 21:58:31 mha Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.82 2007/07/08 19:07:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -480,15 +480,18 @@ test_postmaster_connection(bool do_checkpoint)
 	if (!*portstr)
 		snprintf(portstr, sizeof(portstr), "%d", DEF_PGPORT);
 
-	/* We need to set a connect timeout otherwise on Windows the SCM will probably timeout first */
+	/*
-	snprintf(connstr, sizeof(connstr), "dbname=postgres port=%s connect_timeout=5", portstr);
+	 * We need to set a connect timeout otherwise on Windows the SCM will
+	 * probably timeout first
+	 */
+	snprintf(connstr, sizeof(connstr),
+			 "dbname=postgres port=%s connect_timeout=5", portstr);
 
 	for (i = 0; i < wait_seconds; i++)
 	{
 		if ((conn = PQconnectdb(connstr)) != NULL &&
 			(PQstatus(conn) == CONNECTION_OK ||
-			 (strcmp(PQerrorMessage(conn),
+			 PQconnectionUsedPassword(conn)))
-					 PQnoPasswordSupplied) == 0)))
 		{
 			PQfinish(conn);
 			success = true;

src/bin/pg_dump/pg_backup_db.c

@@ -5,7 +5,7 @@
  *	Implements the basic DB functions used by the archiver.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_db.c,v 1.75 2006/10/04 00:30:05 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_db.c,v 1.76 2007/07/08 19:07:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -123,13 +123,11 @@ ReconnectToServer(ArchiveHandle *AH, const char *dbname, const char *username)
 static PGconn *
 _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 {
-	int			need_pass;
 	PGconn	   *newConn;
-	char	   *password = NULL;
-	int			badPwd = 0;
-	int			noPwd = 0;
 	char	   *newdb;
 	char	   *newuser;
+	char	   *password = NULL;
+	bool		new_pass;
 
 	if (!reqdb)
 		newdb = PQdb(AH->connection);
@@ -152,7 +150,7 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 
 	do
 	{
-		need_pass = false;
+		new_pass = false;
 		newConn = PQsetdbLogin(PQhost(AH->connection), PQport(AH->connection),
 							   NULL, NULL, newdb,
 							   newuser, password);
@@ -161,30 +159,23 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 
 		if (PQstatus(newConn) == CONNECTION_BAD)
 		{
-			noPwd = (strcmp(PQerrorMessage(newConn),
+			if (!PQconnectionUsedPassword(newConn))
-							PQnoPasswordSupplied) == 0);
-			badPwd = (strncmp(PQerrorMessage(newConn),
-						"Password authentication failed for user", 39) == 0);
-
-			if (noPwd || badPwd)
-			{
-				if (badPwd)
-					fprintf(stderr, "Password incorrect\n");
-
-				fprintf(stderr, "Connecting to %s as %s\n",
-						newdb, newuser);
-
-				need_pass = true;
-				if (password)
-					free(password);
-				password = simple_prompt("Password: ", 100, false);
-			}
-			else
 				die_horribly(AH, modulename, "could not reconnect to database: %s",
 							 PQerrorMessage(newConn));
 			PQfinish(newConn);
+
+			if (password)
+				fprintf(stderr, "Password incorrect\n");
+
+			fprintf(stderr, "Connecting to %s as %s\n",
+					newdb, newuser);
+
+			if (password)
+				free(password);
+			password = simple_prompt("Password: ", 100, false);
+			new_pass = true;
 		}
-	} while (need_pass);
+	} while (new_pass);
 
 	if (password)
 		free(password);
@@ -214,7 +205,7 @@ ConnectDatabase(Archive *AHX,
 {
 	ArchiveHandle *AH = (ArchiveHandle *) AHX;
 	char	   *password = NULL;
-	bool		need_pass = false;
+	bool		new_pass;
 
 	if (AH->connection)
 		die_horribly(AH, modulename, "already connected to a database\n");
@@ -235,7 +226,7 @@ ConnectDatabase(Archive *AHX,
 	 */
 	do
 	{
-		need_pass = false;
+		new_pass = false;
 		AH->connection = PQsetdbLogin(pghost, pgport, NULL, NULL,
 									  dbname, username, password);
 
@@ -243,16 +234,15 @@ ConnectDatabase(Archive *AHX,
 			die_horribly(AH, modulename, "failed to connect to database\n");
 
 		if (PQstatus(AH->connection) == CONNECTION_BAD &&
-		 strcmp(PQerrorMessage(AH->connection), PQnoPasswordSupplied) == 0 &&
+			PQconnectionUsedPassword(AH->connection) &&
+			password == NULL &&
 			!feof(stdin))
 		{
 			PQfinish(AH->connection);
-			need_pass = true;
-			free(password);
-			password = NULL;
 			password = simple_prompt("Password: ", 100, false);
+			new_pass = true;
 		}
-	} while (need_pass);
+	} while (new_pass);
 
 	if (password)
 		free(password);

src/bin/pg_dump/pg_dumpall.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.91 2007/05/15 20:20:21 alvherre Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.92 2007/07/08 19:07:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1310,7 +1310,7 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 				const char *pguser, bool require_password, bool fail_on_error)
 {
 	PGconn	   *conn;
-	bool		need_pass = false;
+	bool		new_pass;
 	const char *remoteversion_str;
 	int			my_version;
 	static char *password = NULL;
@@ -1324,7 +1324,7 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 	 */
 	do
 	{
-		need_pass = false;
+		new_pass = false;
 		conn = PQsetdbLogin(pghost, pgport, NULL, NULL, dbname, pguser, password);
 
 		if (!conn)
@@ -1335,17 +1335,15 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 		}
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
-			strcmp(PQerrorMessage(conn), PQnoPasswordSupplied) == 0 &&
+			PQconnectionUsedPassword(conn) &&
+			password == NULL &&
 			!feof(stdin))
 		{
 			PQfinish(conn);
-			need_pass = true;
-			if (password)
-				free(password);
-			password = NULL;
 			password = simple_prompt("Password: ", 100, false);
+			new_pass = true;
 		}
-	} while (need_pass);
+	} while (new_pass);
 
 	/* check to see that the backend connection was successfully made */
 	if (PQstatus(conn) == CONNECTION_BAD)

src/bin/psql/command.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.179 2007/03/03 17:19:11 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.180 2007/07/08 19:07:38 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "command.h"
@@ -1110,11 +1110,11 @@ do_connect(char *dbname, char *user, char *host, char *port)
 	 * If the user asked to be prompted for a password, ask for one now. If
 	 * not, use the password from the old connection, provided the username
 	 * has not changed. Otherwise, try to connect without a password first,
-	 * and then ask for a password if we got the appropriate error message.
+	 * and then ask for a password if needed.
 	 *
-	 * XXX: this behavior is broken. It leads to spurious connection attempts
+	 * XXX: this behavior leads to spurious connection attempts recorded
-	 * in the postmaster's log, and doing a string comparison against the
+	 * in the postmaster's log.  But libpq offers no API that would let us
-	 * returned error message is pretty fragile.
+	 * obtain a password and then continue with the first connection attempt.
 	 */
 	if (pset.getPassword)
 	{
@@ -1141,7 +1141,7 @@ do_connect(char *dbname, char *user, char *host, char *port)
 		 * Connection attempt failed; either retry the connection attempt with
 		 * a new password, or give up.
 		 */
-		if (strcmp(PQerrorMessage(n_conn), PQnoPasswordSupplied) == 0)
+		if (!password && PQconnectionUsedPassword(n_conn))
 		{
 			PQfinish(n_conn);
 			password = prompt_for_password(user);

src/bin/psql/startup.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/startup.c,v 1.140 2007/02/01 19:10:29 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/startup.c,v 1.141 2007/07/08 19:07:38 tgl Exp $
  */
 #include "postgres_fe.h"
 
@@ -108,7 +108,7 @@ main(int argc, char *argv[])
 	char	   *username = NULL;
 	char	   *password = NULL;
 	char	   *password_prompt = NULL;
-	bool		need_pass;
+	bool		new_pass;
 
 	set_pglocale_pgservice(argv[0], "psql");
 
@@ -204,23 +204,22 @@ main(int argc, char *argv[])
 	/* loop until we have a password if requested by backend */
 	do
 	{
-		need_pass = false;
+		new_pass = false;
 		pset.db = PQsetdbLogin(options.host, options.port, NULL, NULL,
 					options.action == ACT_LIST_DB && options.dbname == NULL ?
 							   "postgres" : options.dbname,
 							   username, password);
 
 		if (PQstatus(pset.db) == CONNECTION_BAD &&
-			strcmp(PQerrorMessage(pset.db), PQnoPasswordSupplied) == 0 &&
+			PQconnectionUsedPassword(pset.db) &&
+			password == NULL &&
 			!feof(stdin))
 		{
 			PQfinish(pset.db);
-			need_pass = true;
-			free(password);
-			password = NULL;
 			password = simple_prompt(password_prompt, 100, false);
+			new_pass = true;
 		}
-	} while (need_pass);
+	} while (new_pass);
 
 	free(username);
 	free(password);

src/bin/scripts/common.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/bin/scripts/common.c,v 1.26 2007/04/09 18:21:22 mha Exp $
+ * $PostgreSQL: pgsql/src/bin/scripts/common.c,v 1.27 2007/07/08 19:07:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -100,7 +100,7 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 {
 	PGconn	   *conn;
 	char	   *password = NULL;
-	bool		need_pass = false;
+	bool		new_pass;
 
 	if (require_password)
 		password = simple_prompt("Password: ", 100, false);
@@ -111,7 +111,7 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 	 */
 	do
 	{
-		need_pass = false;
+		new_pass = false;
 		conn = PQsetdbLogin(pghost, pgport, NULL, NULL, dbname, pguser, password);
 
 		if (!conn)
@@ -122,16 +122,15 @@ connectDatabase(const char *dbname, const char *pghost, const char *pgport,
 		}
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
-			strcmp(PQerrorMessage(conn), PQnoPasswordSupplied) == 0 &&
+			PQconnectionUsedPassword(conn) &&
+			password == NULL &&
 			!feof(stdin))
 		{
 			PQfinish(conn);
-			need_pass = true;
-			free(password);
-			password = NULL;
 			password = simple_prompt("Password: ", 100, false);
+			new_pass = true;
 		}
-	} while (need_pass);
+	} while (new_pass);
 
 	if (password)
 		free(password);