- // copy non-matching bits:
- newstring << pattern->Mid(lastpos, m_Matches[idx].rm_so - lastpos);
- // copy replacement:
- newstring << replacement;
- // remember how far we got:
- lastpos = m_Matches[idx].rm_eo;
- replaced ++;
+ // the string possibly contains back references: we need to calculate
+ // the replacement text anew after each match
+ if ( mayHaveBackrefs )
+ {
+ mayHaveBackrefs = false;
+ textNew.clear();
+ textNew.reserve(replacement.length());
+
+ for ( const wxChar *p = replacement.c_str(); *p; p++ )
+ {
+ size_t index = (size_t)-1;
+
+ if ( *p == wxT('\\') )
+ {
+ if ( wxIsdigit(*++p) )
+ {
+ // back reference
+ wxChar *end;
+ index = (size_t)wxStrtoul(p, &end, 10);
+ p = end - 1; // -1 to compensate for p++ in the loop
+ }
+ //else: backslash used as escape character
+ }
+ else if ( *p == wxT('&') )
+ {
+ // treat this as "\0" for compatbility with ed and such
+ index = 0;
+ }
+
+ // do we have a back reference?
+ if ( index != (size_t)-1 )
+ {
+ // yes, get its text
+ size_t start, len;
+ if ( !GetMatch(&start, &len, index) )
+ {
+ wxFAIL_MSG( wxT("invalid back reference") );
+
+ // just eat it...
+ }
+ else
+ {
+ textNew += wxString(
+#ifndef WXREGEX_CONVERT_TO_MB
+ textstr
+#else
+ textstr.data()
+#endif
+ + matchStart + start,
+ *wxConvCurrent, len);
+
+ mayHaveBackrefs = true;
+ }
+ }
+ else // ordinary character
+ {
+ textNew += *p;
+ }
+ }
+ }
+
+ size_t start, len;
+ if ( !GetMatch(&start, &len) )
+ {
+ // we did have match as Matches() returned true above!
+ wxFAIL_MSG( wxT("internal logic error in wxRegEx::Replace") );
+
+ return wxNOT_FOUND;
+ }
+
+ // an insurance against implementations that don't grow exponentially
+ // to ensure building the result takes linear time
+ if (result.capacity() < result.length() + start + textNew.length())
+ result.reserve(2 * result.length());
+
+#ifndef WXREGEX_CONVERT_TO_MB
+ result.append(*text, matchStart, start);
+#else
+ result.append(wxString(textstr.data() + matchStart, *wxConvCurrent, start));
+#endif
+ matchStart += start;
+ result.append(textNew);
+
+ countRepl++;
+
+ matchStart += len;