i18n: use util.pconvert() instead of 'str.replace()' for problematic encoding some problematic encodings use backslash as part of multi-byte characters. util.pconvert() can treat strings in such encodings correctly, if win32mbcs is enabled, but str.replace() can not.

merge with stable

mq: make qprev return the previous applied patch (issue3245) The current behaviour is to return the previous one in the series but at the same time the implementation is buggy because it does not take guarded patches in account.