script_run: use bigger buffer for very long serial commands

If you use script_run at a serial console to run a command more
than 4096 characters long, the wait_serial that waits until the
whole command has made it across the serial connection will
fail, because it uses the default buffer size (4096), so it
will never see the full command. This means there'll be a 90
second timeout before the command is actually run, and a red
frame in the results.

This solves the problem by specifying a larger buffer size when
the command is long.

Issue: https://progress.opensuse.org/issues/153304

Signed-off-by: Adam Williamson <awilliam@redhat.com>

distribution.pm

@@ -127,7 +127,7 @@ sub script_run ($self, $cmd, @args) {
         my $marker = "; echo $str-\$?-" . ($args{output} ? "Comment: $args{output}" : '');
         if (testapi::is_serial_terminal) {
             testapi::type_string($marker);
-            testapi::wait_serial($cmd . $marker, no_regex => 1, quiet => $args{quiet});
+            testapi::wait_serial($cmd . $marker, no_regex => 1, quiet => $args{quiet}, buffer_size => length($cmd) + 128);
             testapi::type_string("\n");
         }
         else {

t/05-distribution.t

@@ -12,6 +12,8 @@ use Test::Warnings qw(:all :report_warnings);
 use Test::Fatal;
 use Test::MockModule;
 
+my @wait_serial_calls;
+
 subtest 'script_run' => sub {
     require distribution;
     my $d = distribution->new;
@@ -33,6 +35,30 @@ subtest 'script_run' => sub {
     lives_ok sub { $d->script_run('foo\&') }, 'escaped terminator is accepted';
     lives_ok sub { $d->script_run('foo && bar') }, 'AND operator is accepted';
     lives_ok sub { $d->script_run('foo "x&"') }, 'quoted & is accepted';
+    $mock_testapi->redefine(wait_serial => sub {
+            my $regexp = shift;
+            push @wait_serial_calls, {
+                regexp => $regexp,
+                timeout => 90,
+                expect_not_found => 0,
+                quiet => undef,
+                no_regex => 0,
+                buffer_size => undef,
+                record_output => undef,
+                @_
+            };
+    });
+    $mock_testapi->redefine(is_serial_terminal => 1);
+    $d->script_run('short_command');
+    # script_run calls wait_serial three times when on a serial
+    # console, the call we want to check - which actually types the
+    # command - is the second
+    my $cmdcall = $wait_serial_calls[1];
+    is $cmdcall->{buffer_size}, 141, 'appropriate buffer size used for short command';
+    @wait_serial_calls = ();
+    $d->script_run('long_command' x 512);
+    $cmdcall = $wait_serial_calls[1];
+    is $cmdcall->{buffer_size}, 6272, 'appropriate buffer size used for long command';
 };
 
 done_testing;