Fixed an issue with keeping a shipped color scheme selected

When the path to the shipped color schemes changes, Qt Creator was
unable to load the chosen color scheme. Now, when it can't find the
color scheme, it will look for it in the default color scheme path.

Reviewed-by: con

src/plugins/texteditor/colorscheme.cpp

@@ -145,8 +145,6 @@ bool ColorScheme::save(const QString &fileName) const
     if (!m_name.isEmpty())
         w.writeAttribute(QLatin1String("name"), m_name);
 
-    Format textFormat = formatFor(QLatin1String(Constants::C_TEXT));
-
     QMapIterator<QString, Format> i(m_formats);
     while (i.hasNext()) {
         const Format &format = i.next().value();

src/plugins/texteditor/fontsettings.cpp

@@ -33,6 +33,8 @@
 #include <utils/qtcassert.h>
 #include <coreplugin/icore.h>
 
+#include <QtCore/QFile>
+#include <QtCore/QFileInfo>
 #include <QtCore/QSettings>
 #include <QtCore/QCoreApplication>
 #include <QtGui/QTextCharFormat>
@@ -114,8 +116,10 @@ bool FontSettings::fromSettings(const QString &category,
 
     if (s->contains(group + QLatin1String(schemeFileNameKey))) {
         // Load the selected color scheme
-        loadColorScheme(s->value(group + QLatin1String(schemeFileNameKey), defaultSchemeFileName()).toString(),
-                        descriptions);
+        QString scheme = s->value(group + QLatin1String(schemeFileNameKey)).toString();
+        if (scheme.isEmpty() || !QFile::exists(scheme))
+            scheme = defaultSchemeFileName(QFileInfo(scheme).fileName());
+        loadColorScheme(scheme, descriptions);
     } else {
         // Load color scheme from ini file
         foreach (const FormatDescription &desc, descriptions) {
@@ -316,11 +320,21 @@ int FontSettings::defaultFontSize()
     return DEFAULT_FONT_SIZE;
 }
 
-QString FontSettings::defaultSchemeFileName()
+/**
+ * Returns the default scheme file name, or the path to a shipped scheme when
+ * one exists with the given \a fileName.
+ */
+QString FontSettings::defaultSchemeFileName(const QString &fileName)
 {
-    QString fileName = Core::ICore::instance()->resourcePath();
-    fileName += QLatin1String("/styles/default.xml");
-    return fileName;
+    QString defaultScheme = Core::ICore::instance()->resourcePath();
+    defaultScheme += QLatin1String("/styles/");
+
+    if (!fileName.isEmpty() && QFile::exists(defaultScheme + fileName))
+        defaultScheme += fileName;
+    else
+        defaultScheme += QLatin1String("default.xml");
+
+    return defaultScheme;
 }
 
 } // namespace TextEditor

src/plugins/texteditor/fontsettings.h

@@ -100,7 +100,7 @@ public:
     static int defaultFontSize();
 
 private:
-    static QString defaultSchemeFileName();
+    static QString defaultSchemeFileName(const QString &fileName = QString());
 
     QString m_family;
     QString m_schemeFileName;