1 files changed, 47 insertions, 4 deletions

diff --git a/xzlib.c b/xzlib.c
index 928bd17..0dcb9f4 100644
--- a/xzlib.c
+++ b/xzlib.c
@@ -182,12 +182,37 @@ xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
     return (xzFile) state;
 }
 
+static int
+xz_compressed(xzFile f) {
+    xz_statep state;
+
+    if (f == NULL)
+        return(-1);
+    state = (xz_statep) f;
+    if (state->init <= 0)
+        return(-1);
+
+    switch (state->how) {
+        case COPY:
+	    return(0);
+	case GZIP:
+	case LZMA:
+	    return(1);
+    }
+    return(-1);
+}
+
 xzFile
 __libxml2_xzopen(const char *path, const char *mode)
 {
     return xz_open(path, -1, mode);
 }
 
+int
+__libxml2_xzcompressed(xzFile f) {
+    return xz_compressed(f);
+}
+
 xzFile
 __libxml2_xzdopen(int fd, const char *mode)
 {
@@ -245,6 +270,20 @@ xz_avail(xz_statep state)
     return 0;
 }
 
+#ifdef HAVE_ZLIB_H
+static int
+xz_avail_zstrm(xz_statep state)
+{
+    int ret;
+    state->strm.avail_in = state->zstrm.avail_in;
+    state->strm.next_in = state->zstrm.next_in;
+    ret = xz_avail(state);
+    state->zstrm.avail_in = (uInt) state->strm.avail_in;
+    state->zstrm.next_in = (Bytef *) state->strm.next_in;
+    return ret;
+}
+#endif
+
 static int
 is_format_xz(xz_statep state)
 {
@@ -314,6 +353,10 @@ is_format_lzma(xz_statep state)
 #define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \
                 (strm->avail_in == 0 ? -1 : \
                  (strm->avail_in--, *(strm->next_in)++)))
+/* Same thing, but from zstrm */
+#define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \
+                (strm->avail_in == 0 ? -1 : \
+                 (strm->avail_in--, *(strm->next_in)++)))
 
 /* Get a four-byte little-endian integer and return 0 on success and the value
    in *ret.  Otherwise -1 is returned and *ret is not modified. */
@@ -324,10 +367,10 @@ gz_next4(xz_statep state, unsigned long *ret)
     unsigned long val;
     z_streamp strm = &(state->zstrm);
 
-    val = NEXT();
-    val += (unsigned) NEXT() << 8;
-    val += (unsigned long) NEXT() << 16;
-    ch = NEXT();
+    val = NEXTZ();
+    val += (unsigned) NEXTZ() << 8;
+    val += (unsigned long) NEXTZ() << 16;
+    ch = NEXTZ();
     if (ch == -1)
         return -1;
     val += (unsigned long) ch << 24;