libpq: Revert the connection option "servicefile"

The following commits are reverted:
* 092f3c63ef, libpq: Add "servicefile" connection option
* 6b1c4d326b, psql: Add variable SERVICEFILE
* 90354030b8, libpq: Fix "servicefile" after fallback to system
  service file

After more review, PGSERVICEFILE is sufficient for the purpose of
specifying a per-session service file.  Some details around this feature
will need more attention before being actually usable, if we ever get
down to it.

One independent piece that has been committed during the v19 development
cycle is df286a5b83, which is kept in the tree as that was an
unrelated change.

Reported-by: Sehrope Sarkuni <sehrope@jackdb.com>
Discussion: https://postgr.es/m/CAH7T-aq+U6GDPO8mr3Gga3KzxGpAE=BSLb38x+R8fvWjzF-H8w@mail.gmail.com
Backpatch-through: 19

doc/src/sgml/libpq.sgml

@@ -2320,19 +2320,6 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
       </listitem>
      </varlistentry>
 
-     <varlistentry id="libpq-connect-servicefile" xreflabel="servicefile">
-      <term><literal>servicefile</literal></term>
-      <listitem>
-       <para>
-        This option specifies the name of the per-user connection service file
-        (see <xref linkend="libpq-pgservice"/>).
-        Defaults to <filename>~/.pg_service.conf</filename>, or
-        <filename>%APPDATA%\postgresql\.pg_service.conf</filename> on
-        Microsoft Windows.
-       </para>
-      </listitem>
-     </varlistentry>
-
      <varlistentry id="libpq-connect-target-session-attrs" xreflabel="target_session_attrs">
       <term><literal>target_session_attrs</literal></term>
       <listitem>
@@ -9170,8 +9157,12 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
       <indexterm>
        <primary><envar>PGSERVICEFILE</envar></primary>
       </indexterm>
-      <envar>PGSERVICEFILE</envar> behaves the same as the
+      <envar>PGSERVICEFILE</envar> specifies the name of the per-user
-      <xref linkend="libpq-connect-servicefile"/> connection parameter.
+      connection service file
+      (see <xref linkend="libpq-pgservice"/>).
+      Defaults to <filename>~/.pg_service.conf</filename>, or
+      <filename>%APPDATA%\postgresql\.pg_service.conf</filename> on
+      Microsoft Windows.
      </para>
     </listitem>
 
@@ -9612,8 +9603,7 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
    On Microsoft Windows, it is named
    <filename>%APPDATA%\postgresql\.pg_service.conf</filename> (where
    <filename>%APPDATA%</filename> refers to the Application Data subdirectory
-   in the user's profile).  A different file name can be specified using the
+   in the user's profile).  A different file name can be specified by
-   <literal>servicefile</literal> key word in a libpq connection string or by
    setting the environment variable <envar>PGSERVICEFILE</envar>.
    The system-wide file is named <filename>pg_service.conf</filename>.
    By default it is sought in the <filename>etc</filename> directory

doc/src/sgml/ref/psql-ref.sgml

@@ -4688,15 +4688,6 @@ bar
         </listitem>
       </varlistentry>
 
-      <varlistentry id="app-psql-variables-servicefile">
-        <term><varname>SERVICEFILE</varname></term>
-        <listitem>
-        <para>
-        The service file name, if applicable.
-        </para>
-        </listitem>
-      </varlistentry>
-
       <varlistentry id="app-psql-variables-shell-error">
        <term><varname>SHELL_ERROR</varname></term>
        <listitem>

src/bin/psql/command.c

@@ -4587,7 +4587,6 @@ SyncVariables(void)
 	char		vbuf[32];
 	const char *server_version;
 	char	   *service_name;
-	char	   *service_file;
 
 	/* get stuff from connection */
 	pset.encoding = PQclientEncoding(pset.db);
@@ -4607,11 +4606,6 @@ SyncVariables(void)
 	if (service_name)
 		pg_free(service_name);
 
-	service_file = get_conninfo_value("servicefile");
-	SetVariable(pset.vars, "SERVICEFILE", service_file);
-	if (service_file)
-		pg_free(service_file);
-
 	/* this bit should match connection_warnings(): */
 	/* Try to get full text form of version, might include "devel" etc */
 	server_version = PQparameterStatus(pset.db, "server_version");
@@ -4641,7 +4635,6 @@ UnsyncVariables(void)
 {
 	SetVariable(pset.vars, "DBNAME", NULL);
 	SetVariable(pset.vars, "SERVICE", NULL);
-	SetVariable(pset.vars, "SERVICEFILE", NULL);
 	SetVariable(pset.vars, "USER", NULL);
 	SetVariable(pset.vars, "HOST", NULL);
 	SetVariable(pset.vars, "PORT", NULL);

src/interfaces/libpq/fe-connect.c

@@ -202,10 +202,6 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 		"Database-Service", "", 20,
 	offsetof(struct pg_conn, pgservice)},
 
-	{"servicefile", "PGSERVICEFILE", NULL, NULL,
-		"Database-Service-File", "", 64,
-	offsetof(struct pg_conn, pgservicefile)},
-
 	{"user", "PGUSER", NULL, NULL,
 		"Database-User", "", 20,
 	offsetof(struct pg_conn, pguser)},
@@ -5081,7 +5077,6 @@ freePGconn(PGconn *conn)
 	free(conn->dbName);
 	free(conn->replication);
 	free(conn->pgservice);
-	free(conn->pgservicefile);
 	free(conn->pguser);
 	if (conn->pgpass)
 	{
@@ -5959,7 +5954,6 @@ static int
 parseServiceInfo(PQconninfoOption *options, PQExpBuffer errorMessage)
 {
 	const char *service = conninfo_getval(options, "service");
-	const char *service_fname = conninfo_getval(options, "servicefile");
 	char		serviceFile[MAXPGPATH];
 	char	   *env;
 	bool		group_found = false;
@@ -5979,13 +5973,10 @@ parseServiceInfo(PQconninfoOption *options, PQExpBuffer errorMessage)
 		return 0;
 
 	/*
-	 * First, try the "servicefile" option in connection string.  Then, try
+	 * Try PGSERVICEFILE if specified, else try ~/.pg_service.conf (if that
-	 * the PGSERVICEFILE environment variable.  Finally, check
+	 * exists).
-	 * ~/.pg_service.conf (if that exists).
 	 */
-	if (service_fname != NULL)
+	if ((env = getenv("PGSERVICEFILE")) != NULL)
-		strlcpy(serviceFile, service_fname, sizeof(serviceFile));
-	else if ((env = getenv("PGSERVICEFILE")) != NULL)
 		strlcpy(serviceFile, env, sizeof(serviceFile));
 	else
 	{
@@ -6017,18 +6008,6 @@ next_file:
 	if (status != 0)
 		return status;
 
-	/* Update servicefile to the file that actually supplied the service */
-	if (group_found && service_fname != NULL &&
-		conninfo_storeval(options, "servicefile", serviceFile,
-						  errorMessage, false, false) == NULL)
-	{
-		/*
-		 * conninfo_storeval already set an error message, that could be only
-		 * an OOM.
-		 */
-		return 3;
-	}
-
 last_file:
 	if (!group_found)
 	{
@@ -6153,17 +6132,7 @@ parseServiceFile(const char *serviceFile,
 				if (strcmp(key, "service") == 0)
 				{
 					libpq_append_error(errorMessage,
-									   "nested \"service\" specifications not supported in service file \"%s\", line %d",
+									   "nested service specifications not supported in service file \"%s\", line %d",
-									   serviceFile,
-									   linenr);
-					result = 3;
-					goto exit;
-				}
-
-				if (strcmp(key, "servicefile") == 0)
-				{
-					libpq_append_error(errorMessage,
-									   "nested \"servicefile\" specifications not supported in service file \"%s\", line %d",
 									   serviceFile,
 									   linenr);
 					result = 3;
@@ -6206,33 +6175,6 @@ parseServiceFile(const char *serviceFile,
 	}
 
 exit:
-
-	/*
-	 * If a service has been successfully found, set the "servicefile" option
-	 * if not already set.  This matters when we use a default service file or
-	 * PGSERVICEFILE, where we want to be able track the value.
-	 */
-	if (*group_found && result == 0)
-	{
-		for (i = 0; options[i].keyword; i++)
-		{
-			if (strcmp(options[i].keyword, "servicefile") != 0)
-				continue;
-
-			/* If value is already set, nothing to do */
-			if (options[i].val != NULL)
-				break;
-
-			options[i].val = strdup(serviceFile);
-			if (options[i].val == NULL)
-			{
-				libpq_append_error(errorMessage, "out of memory");
-				result = 3;
-			}
-			break;
-		}
-	}
-
 	fclose(f);
 
 	return result;

src/interfaces/libpq/libpq-int.h

@@ -392,8 +392,6 @@ struct pg_conn
 	char	   *dbName;			/* database name */
 	char	   *replication;	/* connect as the replication standby? */
 	char	   *pgservice;		/* Postgres service, if any */
-	char	   *pgservicefile;	/* path to a service file containing
-								 * service(s) */
 	char	   *pguser;			/* Postgres username and password, if any */
 	char	   *pgpass;
 	char	   *pgpassfile;		/* path to a file containing password(s) */

src/interfaces/libpq/t/006_service.pl

@@ -49,12 +49,6 @@ copy($srvfile_valid, $srvfile_nested)
   or die "Could not copy $srvfile_valid to $srvfile_nested: $!";
 append_to_file($srvfile_nested, "service=invalid_srv\n");
 
-# Service file with nested "servicefile" defined.
-my $srvfile_nested_2 = "$td/pg_service_nested_2.conf";
-copy($srvfile_valid, $srvfile_nested_2)
-  or die "Could not copy $srvfile_valid to $srvfile_nested_2: $!";
-append_to_file($srvfile_nested_2, 'servicefile=' . $srvfile_default . "\n");
-
 # Set the fallback directory lookup of the service file to the temporary
 # directory of this test.  PGSYSCONFDIR is used if the service file
 # defined in PGSERVICEFILE cannot be found, or when a service file is
@@ -143,14 +137,6 @@ local $ENV{PGSERVICEFILE} = "$srvfile_empty";
 		sql => "SELECT 'connect2_3'",
 		expected_stdout => qr/connect2_3/);
 
-	my $srvfile_empty_win_cared = $srvfile_empty;
-	$srvfile_empty_win_cared =~ s/\\/\\\\/g;
-	$dummy_node->connect_ok(
-		q{service=my_srv servicefile='} . $srvfile_empty_win_cared . q{'},
-		'SERVICEFILE updated when service is found in default pg_service.conf',
-		sql => '\echo :SERVICEFILE',
-		expected_stdout => qr/^\Q$srvfile_default\E$/);
-
 	local $ENV{PGSERVICE} = 'undefined-service';
 	$dummy_node->connect_fails(
 		'',
@@ -168,77 +154,9 @@ local $ENV{PGSERVICEFILE} = "$srvfile_empty";
 
 	$dummy_node->connect_fails(
 		'service=my_srv',
-		'connection with "service" in nested service file',
+		'connection with nested service file',
 		expected_stderr =>
-		  qr/nested "service" specifications not supported in service file/);
+		  qr/nested service specifications not supported in service file/);
-
-	local $ENV{PGSERVICEFILE} = $srvfile_nested_2;
-
-	$dummy_node->connect_fails(
-		'service=my_srv',
-		'connection with "servicefile" in nested service file',
-		expected_stderr =>
-		  qr/nested "servicefile" specifications not supported in service file/
-	);
-}
-
-# Properly escape backslashes in the path, to ensure the generation of
-# correct connection strings.
-my $srvfile_win_cared = $srvfile_valid;
-$srvfile_win_cared =~ s/\\/\\\\/g;
-
-# Checks that the "servicefile" option works as expected
-{
-	$dummy_node->connect_ok(
-		q{service=my_srv servicefile='} . $srvfile_win_cared . q{'},
-		'connection with valid servicefile in connection string',
-		sql => "SELECT 'connect3_1'",
-		expected_stdout => qr/connect3_1/);
-
-	# Encode slashes and backslash
-	my $encoded_srvfile = $srvfile_valid =~ s{([\\/])}{
-		$1 eq '/' ? '%2F' : '%5C'
-	}ger;
-
-	# Additionally encode a colon in servicefile path of Windows
-	$encoded_srvfile =~ s/:/%3A/g;
-
-	$dummy_node->connect_ok(
-		'postgresql:///?service=my_srv&servicefile=' . $encoded_srvfile,
-		'connection with valid servicefile in URI',
-		sql => "SELECT 'connect3_2'",
-		expected_stdout => qr/connect3_2/);
-
-	local $ENV{PGSERVICE} = 'my_srv';
-	$dummy_node->connect_ok(
-		q{servicefile='} . $srvfile_win_cared . q{'},
-		'connection with PGSERVICE and servicefile in connection string',
-		sql => "SELECT 'connect3_3'",
-		expected_stdout => qr/connect3_3/);
-
-	$dummy_node->connect_ok(
-		'postgresql://?servicefile=' . $encoded_srvfile,
-		'connection with PGSERVICE and servicefile in URI',
-		sql => "SELECT 'connect3_4'",
-		expected_stdout => qr/connect3_4/);
-}
-
-# Check that the "servicefile" option takes priority over the PGSERVICEFILE
-# environment variable.
-{
-	local $ENV{PGSERVICEFILE} = 'non-existent-file.conf';
-
-	$dummy_node->connect_fails(
-		'service=my_srv',
-		'connection with invalid PGSERVICEFILE',
-		expected_stderr =>
-		  qr/service file "non-existent-file\.conf" not found/);
-
-	$dummy_node->connect_ok(
-		q{service=my_srv servicefile='} . $srvfile_win_cared . q{'},
-		'connection with both servicefile and PGSERVICEFILE',
-		sql => "SELECT 'connect4_1'",
-		expected_stdout => qr/connect4_1/);
 }
 
 $node->teardown_node;