From e5ec0f8da3602829811d26f03f1a841ceeee64ca Mon Sep 17 00:00:00 2001
From: "jm@0101bb08-14d6-0310-b084-bc0e0c8e3800"
 <jm@0101bb08-14d6-0310-b084-bc0e0c8e3800>
Date: Fri, 18 Jan 2008 04:24:09 +0000
Subject: [PATCH] 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 | 30 ++++++++++++++++--------------
 libentcode/rangedec.c | 30 ++++++++++++++++--------------
 2 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/libentcode/mfrngdec.c b/libentcode/mfrngdec.c
index 77b98e6b..83571c00 100644
--- a/libentcode/mfrngdec.c
+++ b/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
diff --git a/libentcode/rangedec.c b/libentcode/rangedec.c
index 49d26fd7..bfe66452 100644
--- a/libentcode/rangedec.c
+++ b/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