avoid exceptions for non iso characters

Signed-off-by: Greg Wilkins <gregw@webtide.com>

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackContext.java

@@ -461,6 +461,8 @@ public class HpackContext
             if (value != null && value.length() > 0)
             {
                 int huffmanLen = Huffman.octetsNeeded(value);
+                if (huffmanLen < 0)
+                    throw new IllegalStateException("bad value");
                 int lenLen = NBitInteger.octectsNeeded(7, huffmanLen);
                 _huffmanValue = new byte[1 + lenLen + huffmanLen];
                 ByteBuffer buffer = ByteBuffer.wrap(_huffmanValue);

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java

@@ -392,18 +392,18 @@ public class HpackEncoder
         if (huffman)
         {
             // huffman literal value
-            buffer.put((byte)0x80).mark();
+            buffer.put((byte)0x80);
 
-            try
+            int needed = Huffman.octetsNeeded(value);
+            if (needed >= 0)
             {
-                NBitInteger.encode(buffer,7,Huffman.octetsNeeded(value));
+                NBitInteger.encode(buffer, 7, needed);
                 Huffman.encode(buffer, value);
             }
-            catch(Throwable th)
+            else
             {
-                LOG.ignore(th);
+                // Not iso_8859_1
                 byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
-
                 NBitInteger.encode(buffer,7,Huffman.octetsNeeded(bytes));
                 Huffman.encode(buffer,bytes);
             }
@@ -418,7 +418,7 @@ public class HpackEncoder
                 char c = value.charAt(i);
                 if (c < ' ' || c > 127)
                 {
-                    // Not iso_8859_1, so re-encode remaining as UTF-8
+                    // Not iso_8859_1, so re-encode as UTF-8
                     buffer.reset();
                     byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
                     NBitInteger.encode(buffer,7,bytes.length);

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/Huffman.java

@@ -462,7 +462,7 @@ public class Huffman
         {
             char c = s.charAt(i);
             if (c >= 128 || c < ' ')
-                throw new IllegalArgumentException();
+                return -1;
             needed += table[c][1];
         }
 
@@ -481,6 +481,12 @@ public class Huffman
         return (needed + 7) / 8;
     }
 
+    /**
+     * @param table The table to encode by
+     * @param buffer The buffer to encode to
+     * @param s The string to encode
+     * @return True if the string could be encoded, false otherwise (and the buffer may have been modified).
+     */
     private static void encode(final int[][] table, ByteBuffer buffer, String s)
     {
         long current = 0;
@@ -512,6 +518,7 @@ public class Huffman
             buffer.put((byte)(current));
         }
     }
+
     private static void encode(final int[][] table,ByteBuffer buffer,byte[] b)
     {
         long current = 0;

jetty-http2/http2-hpack/src/test/java/org/eclipse/jetty/http2/hpack/HuffmanTest.java

@@ -25,11 +25,13 @@ import java.util.stream.Stream;
 
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
+import org.hamcrest.Matchers;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.junit.jupiter.params.provider.ValueSource;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -77,8 +79,7 @@ public class HuffmanTest
     {
         String s = "bad '" + bad + "'";
 
-        assertThrows(IllegalArgumentException.class,
+        assertThat(Huffman.octetsNeeded(s), Matchers.is(-1));
-            () -> Huffman.octetsNeeded(s));
 
         assertThrows(BufferOverflowException.class,
             () -> Huffman.encode(BufferUtil.allocate(32), s));