fixed writing to wxUniCharRef after its 'parent' iterator was destroyed

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@55285 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/string.h

@@ -673,7 +673,7 @@ public:
       }
 
       reference operator*()
-        { return wxUniCharRef::CreateForString(m_node, m_cur); }
+        { return wxUniCharRef::CreateForString(*str(), m_cur); }
 
       iterator operator+(ptrdiff_t n) const
         { return iterator(str(), wxStringOperations::AddToIter(m_cur, n)); }

include/wx/unichar.h

@@ -183,7 +183,7 @@ private:
 
     // create the reference
 #if wxUSE_UNICODE_UTF8
-    wxUniCharRef(wxStringIteratorNode& node, iterator pos) : m_node(node), m_pos(pos) {}
+    wxUniCharRef(wxString& str, iterator pos) : m_str(str), m_pos(pos) {}
 #else
     wxUniCharRef(iterator pos) : m_pos(pos) {}
 #endif
@@ -195,8 +195,8 @@ public:
     //     that must be used explicitly (this is more than using 'explicit'
     //     keyword on ctor!):
 #if wxUSE_UNICODE_UTF8
-    static wxUniCharRef CreateForString(wxStringIteratorNode& node, iterator pos)
+    static wxUniCharRef CreateForString(wxString& str, iterator pos)
-        { return wxUniCharRef(node, pos); }
+        { return wxUniCharRef(str, pos); }
 #else
     static wxUniCharRef CreateForString(iterator pos)
         { return wxUniCharRef(pos); }
@@ -287,7 +287,7 @@ private:
 private:
     // reference to the string and pointer to the character in string
 #if wxUSE_UNICODE_UTF8
-    wxStringIteratorNode& m_node;
+    wxString& m_str;
 #endif
     iterator m_pos;
 };

src/common/unichar.cpp

@@ -106,8 +106,7 @@ wxUniCharRef& wxUniCharRef::operator=(const wxUniChar& c)
         // code -- in that case, we have to use wxStringImpl::replace() and
         // this invalidates all iterators, so we have to update them too:
 
-        wxString& str = *wx_const_cast(wxString*, m_node.m_str);
+        wxStringImpl& strimpl = m_str.m_impl;
-        wxStringImpl& strimpl = str.m_impl;
 
         int iterDiff = lenNew - lenOld;
         size_t posIdx = m_pos - strimpl.begin();
@@ -121,7 +120,7 @@ wxUniCharRef& wxUniCharRef::operator=(const wxUniChar& c)
         size_t *indexes = indexes_a;
         size_t iterNum = 0;
         wxStringIteratorNode *it;
-        for ( it = str.m_iterators.ptr; it; it = it->m_next, ++iterNum )
+        for ( it = m_str.m_iterators.ptr; it; it = it->m_next, ++iterNum )
         {
             wxASSERT( it->m_iter || it->m_citer );
 
@@ -152,7 +151,7 @@ wxUniCharRef& wxUniCharRef::operator=(const wxUniChar& c)
         // finally, set the iterators to valid values again (note that this
         // updates m_pos as well):
         size_t i;
-        for ( i = 0, it = str.m_iterators.ptr; it; it = it->m_next, ++i )
+        for ( i = 0, it = m_str.m_iterators.ptr; it; it = it->m_next, ++i )
         {
             wxASSERT( i < iterNum );
             wxASSERT( it->m_iter || it->m_citer );

tests/strings/strings.cpp

@@ -59,6 +59,7 @@ private:
         CPPUNIT_TEST( CStrDataOperators );
         CPPUNIT_TEST( CStrDataImplicitConversion );
         CPPUNIT_TEST( ExplicitConversion );
+        CPPUNIT_TEST( IndexedAccess );
     CPPUNIT_TEST_SUITE_END();
 
     void String();
@@ -89,6 +90,7 @@ private:
     void CStrDataOperators();
     void CStrDataImplicitConversion();
     void ExplicitConversion();
+    void IndexedAccess();
 
     DECLARE_NO_COPY_CLASS(StringTestCase)
 };
@@ -826,3 +828,16 @@ void StringTestCase::ExplicitConversion()
     CPPUNIT_ASSERT( CheckStrConstWChar(s, s.wc_str()) );
     CPPUNIT_ASSERT( CheckStrWChar(s, s.wchar_str()) );
 }
+
+void StringTestCase::IndexedAccess()
+{
+    wxString s("bar");
+    CPPUNIT_ASSERT_EQUAL( 'r', s[2] );
+
+    // this tests for a possible bug in UTF-8 based wxString implementation:
+    // the 3rd character of the underlying byte string is going to change, but
+    // the 3rd character of wxString should remain the same
+    s[0] = L'\u00e9';
+    CPPUNIT_ASSERT_EQUAL( 'r', s[2] );
+}
+