Use a better method of setting the internal error that automatically

adjusts for trailing newlines and exception detritus, saving duplicate
code.  Standardize the documentation of the error() method and document
using this in child classes of the generic ACL and Object classes.

Disable printing of errors during connect in Wallet::Server since we're
going to throw our own exception.

2 files changed, 43 insertions, 41 deletions

diff --git a/perl/Wallet/Object/Base.pm b/perl/Wallet/Object/Base.pm
index c3514e3..941e34a 100644
--- a/perl/Wallet/Object/Base.pm
+++ b/perl/Wallet/Object/Base.pm
@@ -88,9 +88,15 @@ sub create {
 # Utility functions
 ##############################################################################
 
-# Returns the current error message of the object, if any.
+# Set or return the error stashed in the object.
 sub error {
-    my ($self) = @_;
+    my ($self, @error) = @_;
+    if (@error) {
+        my $error = join ('', @error);
+        chomp $error;
+        1 while ($error =~ s/ at \S+ line \d+\.?\z//);
+        $self->{error} = $error;
+    }
     return $self->{error};
 }
 
@@ -115,7 +121,7 @@ sub name {
 sub log_action {
     my ($self, $action, $user, $host, $time) = @_;
     unless ($action =~ /^(get|store)\z/) {
-        $self->{error} = "invalid history action $action";
+        $self->error ("invalid history action $action");
         return undef;
     }
 
@@ -143,9 +149,7 @@ sub log_action {
     };
     if ($@) {
         my $id = $self->{type} . ':' . $self->{name};
-        $self->{error} = "cannot update history for $id: $@";
-        chomp $self->{error};
-        $self->{error} =~ s/ at .*$//;
+        $self->error ("cannot update history for $id: $@");
         $self->{dbh}->rollback;
         return undef;
     }
@@ -188,7 +192,7 @@ sub log_set {
 sub _set_internal {
     my ($self, $attr, $value, $user, $host, $time) = @_;
     if ($attr !~ /^[a-z_]+\z/) {
-        $self->{error} = "invalid attribute $attr";
+        $self->error ("invalid attribute $attr");
         return;
     }
     $time ||= time;
@@ -206,9 +210,7 @@ sub _set_internal {
     };
     if ($@) {
         my $id = $self->{type} . ':' . $self->{name};
-        $self->{error} = "cannot set $attr on $id: $@";
-        chomp $self->{error};
-        $self->{error} =~ s/ at .*//;
+        $self->error ("cannot set $attr on $id: $@");
         $self->{dbh}->rollback;
         return;
     }
@@ -219,7 +221,7 @@ sub _set_internal {
 sub _get_internal {
     my ($self, $attr) = @_;
     if ($attr !~ /^[a-z_]+\z/) {
-        $self->{error} = "invalid attribute $attr";
+        $self->error ("invalid attribute $attr");
         return;
     }
     $attr = 'ob_' . $attr;
@@ -235,9 +237,7 @@ sub _get_internal {
 sub acl {
     my ($self, $type, $id, $user, $host, $time) = @_;
     if ($type !~ /^(get|store|show|destroy|flags)\z/) {
-        $self->{error} = "invalid ACL type $type";
-        chomp $self->{error};
-        $self->{error} =~ s/ at .*$//;
+        $self->error ("invalid ACL type $type");
         return;
     }
     my $attr = "acl_$type";
@@ -245,9 +245,7 @@ sub acl {
         my $acl;
         eval { $acl = Wallet::ACL->new ($id, $self->{dbh}) };
         if ($@) {
-            $self->{error} = $@;
-            chomp $self->{error};
-            $self->{error} =~ s/ at .*$//;
+            $self->error ($@);
             return undef;
         }
         return $self->_set_internal ($attr, $acl->id, $user, $host, $time);
@@ -265,7 +263,7 @@ sub expires {
     my ($self, $expires, $user, $host, $time) = @_;
     if ($expires) {
         if ($expires !~ /^\d+\z/ || $expires == 0) {
-            $self->{error} = "malformed expiration time $expires";
+            $self->error ("malformed expiration time $expires");
             return;
         }
         return $self->_set_internal ('expires', $expires, $user, $host, $time);
@@ -284,9 +282,7 @@ sub owner {
         my $acl;
         eval { $acl = Wallet::ACL->new ($owner, $self->{dbh}) };
         if ($@) {
-            $self->{error} = $@;
-            chomp $self->{error};
-            $self->{error} =~ s/ at .*$//;
+            $self->error ($@);
             return undef;
         }
         return $self->_set_internal ('owner', $acl->id, $user, $host, $time);
@@ -309,7 +305,7 @@ sub get { die "Do not instantiate Wallet::Object::Base directly\n"; }
 sub store {
     my ($self, $data, $user, $host, $time) = @_;
     my $id = $self->{type} . ':' . $self->{name};
-    $self->{error} = "cannot store $id: object type is immutable";
+    $self->error ("cannot store $id: object type is immutable");
     return;
 }
 
@@ -346,9 +342,7 @@ sub show {
         @data = $self->{dbh}->selectrow_array ($sql, undef, $type, $name);
     };
     if ($@) {
-        $self->{error} = "cannot retrieve data for ${type}:${name}: $@";
-        chomp $self->{error};
-        $self->{error} =~ s/ at .*$//;
+        $self->error ("cannot retrieve data for ${type}:${name}: $@");
         return undef;
     }
     my $output = '';
@@ -384,9 +378,7 @@ sub destroy {
         $self->{dbh}->commit;
     };
     if ($@) {
-        $self->{error} = "cannot destroy ${type}:${name}: $@";
-        chomp $self->{error};
-        $self->{error} =~ s/ at .*$//;
+        $self->error ("cannot destroy ${type}:${name}: $@");
         $self->{dbh}->rollback;
         return undef;
     }
@@ -487,6 +479,19 @@ true on success and false on failure.  The arguments are used for logging
 and history and should indicate the user and host from which the change is
 made and the time of the change.
 
+=item error([ERROR ...])
+
+Returns the error of the last failing operation or undef if no operations
+have failed.  Callers should call this function to get the error message
+after an undef return from any other instance method.
+
+For the convenience of child classes, this method can also be called with
+one or more error strings.  If so, those strings are concatenated together,
+trailing newlines are removed, any text of the form S<C< at \S+ line
+\d+\.?>> at the end of the message is stripped off, and the result is stored
+as the error.  Only child classes should call this method with an error
+string.
+
 =item error()
 
 Returns the error message from the last failing operation or undef if no
diff --git a/perl/Wallet/Object/Keytab.pm b/perl/Wallet/Object/Keytab.pm
index 313a439..38e0938 100644
--- a/perl/Wallet/Object/Keytab.pm
+++ b/perl/Wallet/Object/Keytab.pm
@@ -123,7 +123,7 @@ sub _kadmin_addprinc {
 sub _kadmin_ktadd {
     my ($self, $principal, $file) = @_;
     unless ($self->_valid_principal ($principal)) {
-        $self->{error} = "invalid principal name: $principal";
+        $self->error ("invalid principal name: $principal");
         return undef;
     }
     if ($Wallet::Config::KEYTAB_REALM) {
@@ -131,11 +131,10 @@ sub _kadmin_ktadd {
     }
     my $output = eval { $self->_kadmin ("ktadd -q -k $file $principal") };
     if ($@) {
-        $self->{error} = $@;
-        chomp $self->{error};
+        $self->error ($@);
         return undef;
     } elsif ($output =~ /^(?:kadmin|ktadd): (.*)/m) {
-        $self->{error} = "error creating keytab for $principal: $1";
+        $self->error ("error creating keytab for $principal: $1");
         return undef;
     }
     return 1;
@@ -147,13 +146,12 @@ sub _kadmin_ktadd {
 sub _kadmin_delprinc {
     my ($self, $principal) = @_;
     unless ($self->_valid_principal ($principal)) {
-        $self->{error} = "invalid principal name: $principal";
+        $self->error ("invalid principal name: $principal");
         return undef;
     }
     my $exists = eval { $self->_kadmin_exists ($principal) };
     if ($@) {
-        $self->{error} = $@;
-        chomp $self->{error};
+        $self->error ($@);
         return undef;
     } elsif (not $exists) {
         return 1;
@@ -163,11 +161,10 @@ sub _kadmin_delprinc {
     }
     my $output = eval { $self->_kadmin ("delprinc -force $principal") };
     if ($@) {
-        $self->{error} = $@;
-        chomp $self->{error};
+        $self->error ($@);
         return undef;
     } elsif ($output =~ /^delete_principal: (.*)/m) {
-        $self->{error} = "error deleting $principal: $1";
+        $self->error ("error deleting $principal: $1");
         return undef;
     }
     return 1;
@@ -200,7 +197,7 @@ sub get {
     my ($self, $user, $host, $time) = @_;
     $time ||= time;
     unless (defined ($Wallet::Config::KEYTAB_TMP)) {
-        $self->{error} = 'KEYTAB_TMP configuration variable not set';
+        $self->error ('KEYTAB_TMP configuration variable not set');
         return undef;
     }
     my $file = $Wallet::Config::KEYTAB_TMP . "/keytab.$$";
@@ -208,7 +205,7 @@ sub get {
     local *KEYTAB;
     unless (open (KEYTAB, '<', $file)) {
         my $princ = $self->{name};
-        $self->{error} = "error opening keytab for principal $princ: $!";
+        $self->error ("error opening keytab for principal $princ: $!");
         return undef;
     }
     local $/;
@@ -216,7 +213,7 @@ sub get {
     my $data = <KEYTAB>;
     if ($!) {
         my $princ = $self->{name};
-        $self->{error} = "error reading keytab for principal $princ: $!";
+        $self->error ("error reading keytab for principal $princ: $!");
         return undef;
     }
     close KEYTAB;