X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5d3e7b52d84580c28df8f754b81363502f917ac7..d45318b8b6857ab6159b37c2f3ddce6a5f68be28:/src/common/gifdecod.cpp

diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 189b524305..f49f473d3b 100644
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -271,17 +271,19 @@ bool wxGIFDecoder::GoPrevFrame(bool cyclic)
 
 bool wxGIFDecoder::GoFrame(int which)
 {
-    int i;
-
     if (!IsAnimation())
         return false;
 
     if ((which >= 1) && (which <= m_nimages))
     {
+        m_image = 1;
         m_pimage = m_pfirst;
 
-        for (i = 0; i < which; i++)
+        while (m_image < which)
+        {
+            m_image++;
             m_pimage = m_pimage->next;
+        }
 
         return true;
     }
@@ -621,7 +623,7 @@ bool wxGIFDecoder::CanRead()
     if ( !m_f->Read(buf, WXSIZEOF(buf)) )
         return false;
 
-    m_f->SeekI(-(off_t)WXSIZEOF(buf), wxFromCurrent);
+    m_f->SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
 
     return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
 }
@@ -752,7 +754,7 @@ int wxGIFDecoder::ReadGIF()
                     transparent = buf[4];
 
                 /* read disposal method */
-                disposal = (buf[1] & 0x1C) - 1;
+                disposal = ((buf[1] & 0x1C) >> 2) - 1;
             }
             else
             /* other extension, skip */
@@ -906,8 +908,8 @@ int wxGIFDecoder::ReadGIF()
             if ((buf[8] & 0x80) == 0x80)
             {
                 ncolors = 2 << (buf[8] & 0x07);
-                off_t pos = m_f->TellI();
-                off_t numBytes = 3 * ncolors;
+                wxFileOffset pos = m_f->TellI();
+                wxFileOffset numBytes = 3 * ncolors;
                 m_f->SeekI(numBytes, wxFromCurrent);
                 if (m_f->TellI() != (pos + numBytes))
                 {