Fix non-simple integer initialization

Altai-man · Feb 8, 2021 · 2078519 · 2078519
1 parent dc724ee
commit 2078519
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Showing 2 changed files with 31 additions and 12 deletions.
diff --git a/lib/ASN/Serializer.pm6 b/lib/ASN/Serializer.pm6
@@ -10,19 +10,29 @@ class ASN::Serializer {
     # INTEGER
     multi method serialize(Int $int is copy where $int.HOW ~~ Metamodel::ClassHOW, Int $index = 2, :$debug, :$mode) {
         my $int-encoded = Buf.new;
-        my $bit-shift-value = 0;
-        my $bit-shift-mask = 0xff;
-        loop {
-            my $byte = $int +& $bit-shift-mask +> $bit-shift-value;
-            if $byte == 0 {
-                $int-encoded.append(0) if $int-encoded.elems == 0;
-                last;
+        my ($is-neg, $limit);
+        if $is-neg = $int < 0 {
+            $int = -$int;
+            $limit = 0x80;
+        } else {
+            $limit = 0x7F;
+        }
+
+        while $int > $limit {
+            $int-encoded.append($int +& 0xFF);
+            $int +>= 8;
+        }
+        $int-encoded.append($int +& 0xFF);
+
+        if $is-neg {
+            $int-encoded = Buf.new($int-encoded.map(0xFF - *));
+            for $int-encoded.kv -> $i, $v {
+                $int-encoded[$i] += 1;
+                last if $int-encoded[$i] <= 0xFF;
+                $int-encoded[$i] = 0x0;
             }
-            $int-encoded.append($byte);
-            # Update operands
-            $bit-shift-value += 8;
-            $bit-shift-mask +<= 8;
         }
+        $int-encoded.append(0xFF) if $is-neg && $int-encoded[* - 1] == 0x7F;
 
         say "Encoding Int ($int) with index $index, resulting in $int-encoded.reverse().perl()" if $debug;
         self!pack($index, $int-encoded.reverse);

diff --git a/t/03-long-integers.t b/t/03-long-integers.t
@@ -6,6 +6,15 @@ is ASN::Parser.parse($buf, Int), -128, 'Parsing of a padded negative value works
 
 use ASN::Serializer;
 
-say ASN::Serializer.serialize(127);
+my @nums = 0, 127, 128, 256, -128, -129;
+my @results = (Buf.new(0x02, 0x01, 0x00), Buf.new(0x02, 0x01, 0x7F),
+               Buf.new(0x02, 0x02, 0x00, 0x80),
+               Buf.new(0x02, 0x02, 0x01, 0x00),
+               Buf.new(0x02, 0x01, 0x80),
+               Buf.new(0x02, 0x02, 0xFF, 0x7F));
+
+for @nums Z @results {
+    is-deeply $_[1], ASN::Serializer.serialize($_[0]), "Can serialize $_[0].raku() into $_[1].raku()";
+}
 
 done-testing;