bogus assert removed, optimized (and removed a bug in process of doing it)

wxString::Trim


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@799 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/string.h

@@ -257,10 +257,10 @@ public:
   size_t Len() const { return GetStringData()->nDataLength; }
     /// string contains any characters?
   bool IsEmpty() const { return Len() == 0; }
-    /// reinitialize string (and free data!)
+    /// reinitialize string (and free memory)
   void Empty()
   {
-    if ( GetStringData()->nDataLength != 0 )
+    if ( !IsEmpty() )
       Reinit();
 
     wxASSERT( GetStringData()->nDataLength == 0 );

src/common/string.cpp

@@ -775,6 +775,15 @@ wxString& wxString::MakeLower()
 // trims spaces (in the sense of isspace) from left or right side
 wxString& wxString::Trim(bool bFromRight)
 {
+  // first check if we're going to modify the string at all
+  if ( !IsEmpty() && 
+       ( 
+        (bFromRight && isspace(GetChar(Len() - 1))) ||
+        (!bFromRight && isspace(GetChar(0u)))
+       )
+     )
+  {
+    // ok, there is at least one space to trim
     CopyBeforeWrite();
 
     if ( bFromRight )
@@ -800,6 +809,7 @@ wxString& wxString::Trim(bool bFromRight)
       memmove(m_pchData, psz, (nDataLength + 1)*sizeof(char));
       GetStringData()->nDataLength = nDataLength;
     }
+  }
 
   return *this;
 }