Fix HttpUtil.getCharset to not throw illegal charset exception (netty…

…#9439)

Motivation:

If the HttpUtil.getCharset method is called with an illegal charset like
"charset=!illegal!" it throws an IllegalCharsetNameException. But the javadoc
states, that defaultCharset is returned if incorrect header value. Since the
client sending the request sets the header value this should not crash.

Modification:

HttpUtil.getCharset catches the IllegalCharsetNameException and returns the
defualt value.

Result:

HttpUtil.getCharset does not throw IllegalCharsetNameException any more.

codec-http/src/main/java/io/netty/handler/codec/http/HttpUtil.java

@@ -18,6 +18,7 @@
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.nio.charset.Charset;
+import java.nio.charset.IllegalCharsetNameException;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -391,15 +392,14 @@ public static Charset getCharset(CharSequence contentTypeValue, Charset defaultC
             if (charsetCharSequence != null) {
                 try {
                     return Charset.forName(charsetCharSequence.toString());
+                } catch (IllegalCharsetNameException ignored) {
+                    // just return the default charset
                 } catch (UnsupportedCharsetException ignored) {
-                    return defaultCharset;
+                    // just return the default charset
                 }
-            } else {
-                return defaultCharset;
             }
-        } else {
-            return defaultCharset;
         }
+        return defaultCharset;
     }
 
     /**

codec-http/src/test/java/io/netty/handler/codec/http/HttpUtilTest.java

@@ -109,6 +109,7 @@ public void testGetCharsetIfNotLastParameter() {
     public void testGetCharset_defaultValue() {
         final String SIMPLE_CONTENT_TYPE = "text/html";
         final String CONTENT_TYPE_WITH_INCORRECT_CHARSET = "text/html; charset=UTFFF";
+        final String CONTENT_TYPE_WITH_ILLEGAL_CHARSET_NAME = "text/html; charset=!illegal!";
 
         HttpMessage message = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
         message.headers().set(HttpHeaderNames.CONTENT_TYPE, SIMPLE_CONTENT_TYPE);
@@ -127,6 +128,15 @@ public void testGetCharset_defaultValue() {
         assertEquals(CharsetUtil.UTF_8, HttpUtil.getCharset(message, StandardCharsets.UTF_8));
         assertEquals(CharsetUtil.UTF_8,
                      HttpUtil.getCharset(CONTENT_TYPE_WITH_INCORRECT_CHARSET, StandardCharsets.UTF_8));
+
+        message.headers().set(HttpHeaderNames.CONTENT_TYPE, CONTENT_TYPE_WITH_ILLEGAL_CHARSET_NAME);
+        assertEquals(CharsetUtil.ISO_8859_1, HttpUtil.getCharset(message));
+        assertEquals(CharsetUtil.ISO_8859_1, HttpUtil.getCharset(CONTENT_TYPE_WITH_ILLEGAL_CHARSET_NAME));
+
+        message.headers().set(HttpHeaderNames.CONTENT_TYPE, CONTENT_TYPE_WITH_ILLEGAL_CHARSET_NAME);
+        assertEquals(CharsetUtil.UTF_8, HttpUtil.getCharset(message, StandardCharsets.UTF_8));
+        assertEquals(CharsetUtil.UTF_8,
+                HttpUtil.getCharset(CONTENT_TYPE_WITH_ILLEGAL_CHARSET_NAME, StandardCharsets.UTF_8));
     }
 
     @Test