There is a missmatch between the Java definition and the native JNI implementation for the "interlace" parameter of the awt_image_GifImageDecoder_parseImage() method:

src/java.desktop/share/classes/sun/awt/image/GifImageDecoder.java

    private native boolean parseImage(
                                      int x, int y,
                                      int width, int height,
                                      boolean interlace, <-------- the boolean type in java code
                                      int initCodeSize,
                                      byte block[], byte rasline[],
                                      IndexColorModel model);

src/java.desktop/share/native/libawt/awt/image/gif/gifdecoder.c

JNIEXPORT jboolean JNICALL
Java_sun_awt_image_GifImageDecoder_parseImage(JNIEnv *env, jobject this,
                                              jint relx, jint rely,
                                              jint width, jint height,
                                              jint interlace, <--- wrongly cast to the int type in the native code
                                              jint initCodeSize,
                                              jbyteArray blockh,
                                              jbyteArray raslineh,
                                              jobject cmh)
{