make string at least empty (instead of containing garbage) if malloc() failed

[wxWidgets.git] / src / common / zipstrm.cpp

diff --git a/src/common/zipstrm.cpp b/src/common/zipstrm.cpp
index 70e700e651d508493de12dd2848b268004111c6c..1ed942c0eac984ac65d2c023bd7642ec2703676a 100644 (file)
--- a/src/common/zipstrm.cpp
+++ b/src/common/zipstrm.cpp
@@ -17,13 +17,14 @@
   #pragma hdrstop
 #endif
 
-#if wxUSE_STREAMS && wxUSE_ZIPSTREAM && wxUSE_ZLIB 
+#if wxUSE_STREAMS && wxUSE_ZIPSTREAM && wxUSE_ZLIB
 
 #include "wx/log.h"
 #include "wx/intl.h"
 #include "wx/stream.h"
 #include "wx/wfstream.h"
 #include "wx/zipstrm.h"
+#include "wx/utils.h"
 
 /* Not the right solution (paths in makefiles) but... */
 #ifdef __BORLANDC__
@@ -39,33 +40,33 @@ wxZipInputStream::wxZipInputStream(const wxString& archive, const wxString& file
 
     m_Pos = 0;
     m_Size = 0;
-    m_Archive = (void*) unzOpen(archive.mb_str(wxConvFile));
-    if (m_Archive == NULL) 
+    m_Archive = (void*) unzOpen(archive.mb_str());
+    if (m_Archive == NULL)
     {
-        m_lasterror = wxStream_READ_ERR;
+        m_lasterror = wxSTREAM_READ_ERROR;
         return;
     }
-    if (unzLocateFile((unzFile)m_Archive, file.mb_str(wxConvFile), 0) != UNZ_OK) 
+    if (unzLocateFile((unzFile)m_Archive, file.mb_str(), 0) != UNZ_OK)
     {
-        m_lasterror = wxStream_READ_ERR;
+        m_lasterror = wxSTREAM_READ_ERROR;
         return;
     }
-    
+
     unzGetCurrentFileInfo((unzFile)m_Archive, &zinfo, (char*) NULL, 0, (void*) NULL, 0, (char*) NULL, 0);
 
-    if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK) 
+    if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK)
     {
-        m_lasterror = wxStream_READ_ERR;
+        m_lasterror = wxSTREAM_READ_ERROR;
         return;
     }
-    m_Size = zinfo.uncompressed_size;
+    m_Size = (size_t)zinfo.uncompressed_size;
 }
 
 
 
 wxZipInputStream::~wxZipInputStream()
 {
-    if (m_Archive) 
+    if (m_Archive)
     {
         if (m_Size != 0)
             unzCloseCurrentFile((unzFile)m_Archive);
@@ -73,13 +74,32 @@ wxZipInputStream::~wxZipInputStream()
     }
 }
 
+bool wxZipInputStream::Eof() const
+{
+    wxASSERT_MSG( m_Pos <= (off_t)m_Size,
+                  _T("wxZipInputStream: invalid current position") );
+
+    return m_Pos >= (off_t)m_Size;
+}
 
 
 size_t wxZipInputStream::OnSysRead(void *buffer, size_t bufsize)
 {
-    if (m_Pos + bufsize > m_Size) bufsize = m_Size - m_Pos;
+    wxASSERT_MSG( m_Pos <= (off_t)m_Size,
+                  _T("wxZipInputStream: invalid current position") );
+
+    if ( m_Pos >= (off_t)m_Size )
+    {
+        m_lasterror = wxSTREAM_EOF;
+        return 0;
+    }
+
+    if (m_Pos + bufsize > m_Size)
+        bufsize = m_Size - m_Pos;
+
     unzReadCurrentFile((unzFile)m_Archive, buffer, bufsize);
     m_Pos += bufsize;
+
     return bufsize;
 }
 
@@ -87,10 +107,14 @@ size_t wxZipInputStream::OnSysRead(void *buffer, size_t bufsize)
 
 off_t wxZipInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
 {
+    // NB: since ZIP files don't natively support seeking, we have to 
+    //     implement a brute force workaround -- reading all the data
+    //     between current and the new position (or between beginning of 
+    //     the file and new position...)
+
     off_t nextpos;
-    void *buf;
 
-    switch (mode) 
+    switch ( mode )
     {
         case wxFromCurrent : nextpos = seek + m_Pos; break;
         case wxFromStart : nextpos = seek; break;
@@ -98,23 +122,33 @@ off_t wxZipInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
         default : nextpos = m_Pos; break; /* just to fool compiler, never happens */
     }
 
-    // cheated seeking :
-    if (nextpos > m_Pos) 
+    size_t toskip = 0;
+    if ( nextpos > m_Pos )
     {
-        buf = malloc(nextpos - m_Pos);
-        unzReadCurrentFile((unzFile)m_Archive, buf, nextpos -  m_Pos);
-        free(buf);
+        toskip = nextpos - m_Pos;
     }
-    else if (nextpos < m_Pos) {
+    else
+    {
         unzCloseCurrentFile((unzFile)m_Archive);
-        if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK) 
-       {
-            m_lasterror = wxStream_READ_ERR;
+        if (unzOpenCurrentFile((unzFile)m_Archive) != UNZ_OK)
+        {
+            m_lasterror = wxSTREAM_READ_ERROR;
             return m_Pos;
         }
-        buf = malloc(nextpos);
-        unzReadCurrentFile((unzFile)m_Archive, buf, nextpos);
-        free(buf);
+        toskip = nextpos;
+    }
+        
+    if ( toskip > 0 )
+    {
+        const size_t BUFSIZE = 4096;
+        size_t sz;
+        char buffer[BUFSIZE];
+        while ( toskip > 0 )
+        {
+            sz = wxMin(toskip, BUFSIZE);
+            unzReadCurrentFile((unzFile)m_Archive, buffer, sz);
+            toskip -= sz;
+        }
     }
 
     m_Pos = nextpos;
@@ -122,4 +156,4 @@ off_t wxZipInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
 }
 
 #endif
-  // wxUSE_STREAMS && wxUSE_ZIPSTREAM && wxUSE_ZLIB 
+  // wxUSE_STREAMS && wxUSE_ZIPSTREAM && wxUSE_ZLIB