X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/378b05f7f86eda83452d67f182afc62a0f9b982f..5ea6dbbfff67d1dfad08044ab721ba56425ef6e1:/src/common/string.cpp

diff --git a/src/common/string.cpp b/src/common/string.cpp
index 60fcb535a7..ed777353a7 100644
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -107,7 +107,7 @@ extern const wxChar WXDLLEXPORT *wxEmptyString = &g_strEmpty.dummy;
 //       function wxVsnprintfA (A for ANSI), should also find one for Unicode
 //       strings in Unicode build
 #ifdef __WXMSW__
-    #ifdef __VISUALC__
+    #if defined(__VISUALC__) || defined(wxUSE_NORLANDER_HEADERS)
         #define wxVsnprintfA     _vsnprintf
     #endif
 #else   // !Windows
@@ -200,7 +200,15 @@ extern int WXDLLEXPORT wxVsnprintf(wxChar *buf, size_t len,
 
     return iLen;
 #else // ANSI
-    return wxVsnprintfA(buf, len, format, argptr);
+    // vsnprintf() will not terminate the string with '\0' if there is not
+    // enough place, but we want the string to always be NUL terminated
+    int rc = wxVsnprintfA(buf, len - 1, format, argptr);
+    if ( rc == -1 )
+    {
+        buf[len] = 0;
+    }
+
+    return rc;
 #endif // Unicode/ANSI
 }
 
@@ -391,13 +399,35 @@ void wxString::AllocBeforeWrite(size_t nLen)
 
   // must not share string and must have enough space
   wxStringData* pData = GetStringData();
-  if ( pData->IsShared() || (nLen > pData->nAllocLength) ) {
+  if ( pData->IsShared() || pData->IsEmpty() ) {
     // can't work with old buffer, get new one
     pData->Unlock();
     AllocBuffer(nLen);
   }
   else {
-    // update the string length
+    if ( nLen > pData->nAllocLength ) {
+      // realloc the buffer instead of calling malloc() again, this is more
+      // efficient
+      STATISTICS_ADD(Length, nLen);
+
+      nLen += EXTRA_ALLOC;
+
+      wxStringData *pDataOld = pData;
+      pData = (wxStringData*)
+          realloc(pData, sizeof(wxStringData) + (nLen + 1)*sizeof(wxChar));
+      if ( !pData ) {
+        // out of memory
+        free(pDataOld);
+
+        // FIXME we're going to crash...
+        return;
+      }
+
+      pData->nAllocLength = nLen;
+      m_pchData = pData->data();
+    }
+
+    // now we have enough space, just update the string length
     pData->nDataLength = nLen;
   }
 
@@ -429,11 +459,15 @@ void wxString::Alloc(size_t nLen)
     else {
       nLen += EXTRA_ALLOC;
 
+      wxStringData *pDataOld = pData;
       wxStringData *p = (wxStringData *)
         realloc(pData, sizeof(wxStringData) + (nLen + 1)*sizeof(wxChar));
 
       if ( p == NULL ) {
-        // @@@ what to do on memory error?
+        // don't leak memory
+        free(pDataOld);
+
+        // FIXME what to do on memory error?
         return;
       }
 
@@ -451,13 +485,16 @@ void wxString::Shrink()
 {
   wxStringData *pData = GetStringData();
 
-  // this variable is unused in release build, so avoid the compiler warning by
-  // just not declaring it
+  // this variable is unused in release build, so avoid the compiler warning
+  // by just not declaring it
 #ifdef __WXDEBUG__
   void *p =
 #endif
   realloc(pData, sizeof(wxStringData) + (pData->nDataLength + 1)*sizeof(wxChar));
 
+  // we rely on a reasonable realloc() implementation here - so far I haven't
+  // seen any which wouldn't behave like this
+
   wxASSERT( p != NULL );  // can't free memory?
   wxASSERT( p == pData ); // we're decrementing the size - block shouldn't move!
 }
@@ -1606,17 +1643,6 @@ size_t wxString::find_last_not_of(wxChar ch, size_t nStart) const
     return npos;
 }
 
-wxString wxString::substr(size_t nStart, size_t nLen) const
-{
-  // npos means 'take all'
-  if ( nLen == npos )
-    nLen = 0;
-
-  wxASSERT( nStart + nLen <= Len() );
-
-  return wxString(c_str() + nStart, nLen == npos ? 0 : nLen);
-}
-
 wxString& wxString::erase(size_t nStart, size_t nLen)
 {
   wxString strTmp(c_str(), nStart);