[LyX/master] Fix the fix to the decimal separator problem with Qt5

[Juergen Spitzmueller]

commit 138bb4d14f92e347104cc41caa70fa2f7c31dc5a
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Sat Jul 27 11:18:16 2013 +0200

    Fix the fix to the decimal separator problem with Qt5

diff --git a/src/frontends/qt4/qt_helpers.cpp b/src/frontends/qt4/qt_helpers.cpp
index fdd12a1..c816021 100644
--- a/src/frontends/qt4/qt_helpers.cpp
+++ b/src/frontends/qt4/qt_helpers.cpp
@@ -75,6 +75,23 @@ FileName imageLibFileSearch(QString & dir, QString const & 
name,
        return fn;
 }
 
+namespace {
+
+double locstringToDouble(QString const str)
+{
+       QLocale loc;
+       bool ok;
+       double res = loc.toDouble(str, &ok);
+       if (!ok) {
+               // Fall back to C
+               QLocale c(QLocale::C);
+               res = c.toDouble(str);
+       }
+       return res;
+}
+
+} // namespace anon
+
 
 namespace frontend {
 
@@ -90,7 +107,7 @@ string widgetsToLength(QLineEdit const * input, LengthCombo 
const * combo)
 
        Length::UNIT const unit = combo->currentLengthItem();
 
-       return Length(length.trimmed().toDouble(), unit).asString();
+       return Length(locstringToDouble(length.trimmed()), unit).asString();
 }
 
 
@@ -113,7 +130,7 @@ Length widgetsToLength(QLineEdit const * input, QComboBox 
const * combo)
                }
        }
 
-       return Length(length.trimmed().toDouble(), unit);
+       return Length(locstringToDouble(length.trimmed()), unit);
 }
 
 
@@ -163,23 +180,19 @@ double widgetToDouble(QLineEdit const * input)
        if (text.isEmpty())
                return 0.0;
 
-       return text.trimmed().toDouble();
+       return locstringToDouble(text.trimmed());
 }
 
 
 string widgetToDoubleStr(QLineEdit const * input)
 {
-       QString const text = input->text();
-       if (text.isEmpty())
-               return string();
-
-       return convert<string>(text.trimmed().toDouble());
+       return convert<string>(widgetToDouble(input));
 }
 
 
 void doubleToWidget(QLineEdit * input, double const & value, char f, int prec)
 {
-       QLocale loc("C");
+       QLocale loc;
        loc.setNumberOptions(QLocale::OmitGroupSeparator);
        input->setText(loc.toString(value, f, prec));
 }