decomp: remove the free_dest argument

Since the decompress function ALWAYS returns allocated memory we get a
lot simpler code by removing the ability to return data unallocated.

src/comp.c

@@ -80,7 +80,6 @@ comp_method_none_decomp(LIBSSH2_SESSION * session,
                         unsigned char **dest,
                         size_t *dest_len,
                         size_t payload_limit,
-                        int *free_dest,
                         const unsigned char *src,
                         size_t src_len, void **abstract)
 {
@@ -89,9 +88,6 @@ comp_method_none_decomp(LIBSSH2_SESSION * session,
     (void) abstract;
     *dest = (unsigned char *) src;
     *dest_len = src_len;
-
-    *free_dest = 0;
-
     return 0;
 }
 
@@ -222,7 +218,6 @@ comp_method_zlib_decomp(LIBSSH2_SESSION * session,
                         unsigned char **dest,
                         size_t *dest_len,
                         size_t payload_limit,
-                        int *free_dest,
                         const unsigned char *src,
                         size_t src_len, void **abstract)
 {
@@ -234,22 +229,16 @@ comp_method_zlib_decomp(LIBSSH2_SESSION * session,
     int limiter = 0;
 
     /* If strm is null, then we have not yet been initialized. */
-    if (strm == NULL) {
-        *dest = (unsigned char *) src;
-        *dest_len = src_len;
-
-        *free_dest = 0;
-        return 0;
-    }
+    if (strm == NULL)
+        return _libssh2_error(session, LIBSSH2_ERROR_COMPRESS,
+                              "decompression unitilized");;
 
     /* In practice they never come smaller than this */
-    if (out_maxlen < 25) {
+    if (out_maxlen < 25)
         out_maxlen = 25;
-    }
 
-    if (out_maxlen > (int) payload_limit) {
+    if (out_maxlen > (int) payload_limit)
         out_maxlen = payload_limit;
-    }
 
     strm->next_in = (unsigned char *) src;
     strm->avail_in = src_len;
@@ -340,7 +329,6 @@ comp_method_zlib_decomp(LIBSSH2_SESSION * session,
 
     *dest = (unsigned char *) out;
     *dest_len = out_maxlen - strm->avail_out;
-    *free_dest = 1;
 
     return 0;
 }

src/libssh2_priv.h

@@ -892,9 +892,11 @@ struct _LIBSSH2_COMP_METHOD
                  void **abstract);
     int (*decomp) (LIBSSH2_SESSION *session,
                    unsigned char **dest,
-                   size_t *dest_len, size_t payload_limit,
-                   int *free_dest, const unsigned char *src,
-                   size_t src_len, void **abstract);
+                   size_t *dest_len,
+                   size_t payload_limit,
+                   const unsigned char *src,
+                   size_t src_len,
+                   void **abstract);
     int (*dtor) (LIBSSH2_SESSION * session, int compress, void **abstract);
 };
 

src/transport.c

@@ -198,47 +198,18 @@ fullpacket(LIBSSH2_SESSION * session, int encrypted /* 1 or 0 */ )
         if (session->remote.comp && session->remote.comp->compress) {
             unsigned char *data;
             size_t data_len;
-            int free_payload = 1;
-
             rc = session->remote.comp->decomp(session,
                                               &data, &data_len,
                                               LIBSSH2_PACKET_MAXDECOMP,
-                                              &free_payload,
                                               p->payload,
                                               session->fullpacket_payload_len,
                                               &session->remote.comp_abstract);
-            if(rc) {
-                LIBSSH2_FREE(session, p->payload);
+            LIBSSH2_FREE(session, p->payload);
+            if(rc)
                 return rc;
-            }
 
-            if (free_payload) {
-                LIBSSH2_FREE(session, p->payload);
-                p->payload = data;
-                session->fullpacket_payload_len = data_len;
-            } else {
-                if (data == p->payload) {
-                    /* It's not to be freed, because the
-                     * compression layer reused payload, So let's
-                     * do the same!
-                     */
-                    session->fullpacket_payload_len = data_len;
-                } else {
-                    /* No comp_method actually lets this happen,
-                     * but let's prepare for the future */
-
-                    LIBSSH2_FREE(session, p->payload);
-
-                    /* We need a freeable struct otherwise the
-                     * brigade won't know what to do with it */
-                    p->payload = LIBSSH2_ALLOC(session, data_len);
-                    if (!p->payload)
-                        return LIBSSH2_ERROR_ALLOC;
-
-                    memcpy(p->payload, data, data_len);
-                    session->fullpacket_payload_len = data_len;
-                }
-            }
+            p->payload = data;
+            session->fullpacket_payload_len = data_len;
         }
 
         session->fullpacket_packet_type = p->payload[0];