Fix bugs in showing backtrace when stopped in a call

lib/Devel/Trepan/CmdProcessor/Frame.pm

@@ -62,7 +62,7 @@ sub print_stack_entry()
     }
 
     my $lineno = $frame->{line} || '??';
-    my $addr = $opts->{displayop} ? sprintf("0x%x ", $frame->{addr}) : '';
+    my $addr = $opts->{displayop} && $frame->{addr} ? sprintf("0x%x ", $frame->{addr}) : '';
     if ($opts->{short}) {
         my $fn = $s; # @_ >= 4 ? $_[3] : $s;
 	my $msg = sprintf("%s%s%s%s from %s:%d",

lib/Devel/Trepan/DB/Backtrace.pm

@@ -1,5 +1,6 @@
 use warnings; no warnings 'redefine';
 use English qw( -no_match_vars );
+use B;
 
 =pod
 
@@ -76,7 +77,8 @@ sub backtrace($;$$$) {
     }
 
     $count += $i;
-    # print "++count: $count, i $i\n";
+    # print "++count: $count, i $i $DB::event\n"; # XX debug
+    $i -= 2 if $DB::event eq 'call';
 
     my ( @a, $args_ary );
     my @callstack = ();
@@ -97,7 +99,7 @@ sub backtrace($;$$$) {
     {
 	my $addr = Devel::Callsite::callsite($i);
 
-        ## print "++file: $file, line $line $fn\n" if $DB::DEBUGME;
+        ## print "++file: $file, line $line $fn\n"; # XX if $DB::DEBUGME;
         $i++;
         next if $pkg eq 'DB' && ($fn eq 'sub' || $fn eq 'lsub' ||
 				 $file =~ m{Devel/Trepan/DB/Sub\.pm$});
@@ -188,18 +190,36 @@ sub backtrace($;$$$) {
         # last if $signal;
     } ## end for ($i = $skip ; $i < ...
 
+    ## use Data::Printer; Data::Printer::p @callstack; # XXX
+
     # The function and args for the stopped line is DB::DB,
     # but we want it to be the function and args of the last call.
+    # Se we need to adjust those in @callstack.
     # And the function and args for the file and line that called us
     # should also be the prior function and args.
     if ($scan_for_DB_sub) {
-        for (my $i=1; $i <= $#callstack; $i++) {
-            $callstack[$i-1]->{args} = $callstack[$i]->{args};
-            $callstack[$i-1]->{fn} = $callstack[$i]->{fn};
-        }
-        $callstack[$i]{args} = undef;
-        $callstack[$i]{fn}   = undef;
+	my $len = @callstack;
+	if ($len) {
+	    for (my $i=1; $i < $len; $i++) {
+		$callstack[$i-1]->{args} = $callstack[$i]->{args};
+		$callstack[$i-1]->{fn} = $callstack[$i]->{fn};
+	    }
+	    # $callstack[$len]->{args} = undef;
+	    # $callstack[$len]->{fn}   = undef;
+	}
+    }
+
+    if ($DB::event eq 'call') {
+        unshift @callstack, {
+	    addr      => $DB::addr,
+	    file      => $DB::filename,
+	    fn        => $DB::subroutine,
+	    line      => $DB::lineno,
+	    pkg       => $DB::package,
+	    wantarray => $DB::wantarray ? $DB::wantarray : '',
+	};
     }
+    # use Data::Printer; Data::Printer::p @callstack;
 
     @callstack;
 }

lib/Devel/Trepan/DB/Sub.pm

@@ -6,6 +6,7 @@ use warnings; no warnings 'redefine'; use utf8;
 no warnings 'once';
 use English qw( -no_match_vars );
 use version;
+use B;
 
 use constant SINGLE_STEPPING_EVENT =>   1;
 use constant NEXT_STEPPING_EVENT   =>   2;
@@ -236,9 +237,14 @@ sub DB::sub {
     if (defined($DB::running) && $DB::running == 1) {
 	local @DB::_ = @_;
 	local(*DB::dbline) = "::_<$DB::filename";
+
+	# FIXME: this isn't quite right;
+	$DB::addr = +B::svref_2object(\$DB::subroutine);
+
 	check_for_stop();
     }
 
+    $DB::wantarray = wantarray;
     if ($DB::sub eq 'DESTROY' or
         substr($DB::sub, -9) eq '::DESTROY' or not defined wantarray) {
         &$DB::sub;
@@ -335,6 +341,10 @@ sub DB::lsub : lvalue {
     push_DB_single_and_set();
 
     local(*DB::dbline) = "::_<$DB::filename";
+
+    # FIXME: this isn't quite right;
+    $DB::addr = +B::svref_2object(\$DB::subroutine);
+
     check_for_stop();
 
     if (wantarray) {

lib/Devel/Trepan/Processor/Frame.pm

@@ -105,18 +105,7 @@ sub frame_setup($$)
 		$self->{gave_stack_trunc_warning} = 1;
 	    }
 	    $stack_size = $computed_stack_depth;
-	    if ($self->{event} eq 'call') {
-		no warnings 'once';  # for DB:: names below
-		$frames[0] =
-		     {
-			 file      => $DB::filename,
-			 fn        => $DB::subroutine,
-			 line      => $DB::lineno,
-			 pkg       => $DB::package,
-			 # FIXME: more later...
-		     };
-
-	    }
+	    $stack_size++ if $self->{event} eq 'call';
         }
         $self->{frames} = \@frames;
         $self->{stack_size}    = $stack_size;

t/data/breakcall.cmd

@@ -1,6 +1,7 @@
 # Test "To see that we can break on a subroutine call"
 # use with example/callbug.pl
 c iamnotok
+where
 $_[0]
 break 6
 quit

t/data/breakcall.right

@@ -2,6 +2,8 @@
 if (scalar @ARGV) {
 -> main::(callbug.pl:4)
 sub iamnotok {
+--> #0 1 = main::iamnotok in file `callbug.pl' at line 4
+    #1 file `callbug.pl' at line 9
 $DB::D[0] = foo
 Breakpoint 2 set in callbug.pl at line 6
 trepan.pl: That's all, folks...