Reverted some of Timothy's changes to the range decoding that were causing...

Reverted some of Timothy's changes to the range decoding that were causing decode random decode problems at the end of the stream (but only once in a while).

git-svn-id: http://svn.xiph.org/trunk/ghost@14413 0101bb08-14d6-0310-b084-bc0e0c8e3800

libentcode/mfrngdec.c

@@ -137,24 +137,26 @@ static int ec_dec_in(ec_dec *_this){
   int ret;
   ret=ec_byte_read1(_this->buf);
   if(ret<0){
-    long bytes;
+    unsigned char *buf;
+    long           bytes;
     bytes=ec_byte_bytes(_this->buf);
+    buf=ec_byte_get_buffer(_this->buf);
     /*Breaking abstraction: don't do this at home, kids.*/
-    if(_this->buf->storage==bytes&&bytes>0){
-      unsigned char *buf;
-      buf=ec_byte_get_buffer(_this->buf);
-      /*If we end in a string of 0 or more EC_FOF_RSV1 bytes preceded by a
-         zero, return an extra EC_FOF_RSV1 byte.*/
-      do bytes--;
-      while(bytes>0&&buf[bytes]==EC_FOF_RSV1);
-      if(!buf[bytes])ret=EC_FOF_RSV1;
+    if(_this->buf->storage==bytes){
+      ec_byte_adv1(_this->buf);
+      if(bytes>0){
+        unsigned char *p;
+        p=buf+bytes;
+        /*If we end in a string of 0 or more EC_FOF_RSV1 bytes preceded by a
+           zero, return an extra EC_FOF_RSV1 byte.*/
+        do p--;
+        while(p>buf&&p[0]==EC_FOF_RSV1);
+        if(!p[0])return EC_FOF_RSV1;
+      }
     }
-    else ret=0;
-    /*Needed to make sure the above conditional only triggers once, and to keep
-       oc_dec_tell() operating correctly.*/
-    ec_byte_adv1(_this->buf);
+    return 0;
   }
-  return ret;
+  else return ret;
 }
 
 /*Normalizes the contents of dif and rng so that rng lies entirely in the

libentcode/rangedec.c

@@ -120,24 +120,26 @@ static int ec_dec_in(ec_dec *_this){
   int ret;
   ret=ec_byte_read1(_this->buf);
   if(ret<0){
-    long bytes;
+    unsigned char *buf;
+    long           bytes;
     bytes=ec_byte_bytes(_this->buf);
+    buf=ec_byte_get_buffer(_this->buf);
     /*Breaking abstraction: don't do this at home, kids.*/
-    if(_this->buf->storage==bytes&&bytes>0){
-      unsigned char *buf;
-      buf=ec_byte_get_buffer(_this->buf);
-      /*If we end in a string of 0 or more EC_FOF_RSV1 bytes preceded by a
-         zero, return an extra EC_FOF_RSV1 byte.*/
-      do bytes--;
-      while(bytes>0&&buf[bytes]==EC_FOF_RSV1);
-      if(!buf[bytes])ret=EC_FOF_RSV1;
+    if(_this->buf->storage==bytes){
+      ec_byte_adv1(_this->buf);
+      if(bytes>0){
+        unsigned char *p;
+        p=buf+bytes;
+        /*If we end in a string of 0 or more EC_FOF_RSV1 bytes preceded by a
+           zero, return an extra EC_FOF_RSV1 byte.*/
+        do p--;
+        while(p>buf&&p[0]==EC_FOF_RSV1);
+        if(!p[0])return EC_FOF_RSV1;
+      }
     }
-    else ret=0;
-    /*Needed to make sure the above conditional only triggers once, and to keep
-       oc_dec_tell() operating correctly.*/
-    ec_byte_adv1(_this->buf);
+    return 0;
   }
-  return ret;
+  else return ret;
 }
 
 /*Normalizes the contents of dif and rng so that rng lies entirely in the