API dox: state explicitly expected encoding for KConfig key & group names

While the API might have been once designed to allow random byte strings
to be used as ids and only converted QString to UTF-8, the current
implementation in many places assumes the byte strings passed via
const char* or QByteArray are also in of UTF-8 encoding
(or at least ASCII7-only).
See e.g. KConfigGroup::entryMap() or KConfigGroup::name().

Stating the supported encoding explicitly should avoid any misassumptions.

src/core/kconfigbase.h

@@ -81,37 +81,78 @@ public:
     /**
      * Returns true if the specified group is known about.
      *
-     * @param group The group to search for.
+     * @param group name of group to search for
      * @return true if the group exists.
      */
     bool hasGroup(const QString &group) const;
+    /**
+     * Overload for hasGroup(const QString&) const
+     *
+     * @param group name of group to search for, encoded in UTF-8
+     */
     bool hasGroup(const char *group) const;
+    /**
+     * Overload for hasGroup(const QString&) const
+     *
+     * @param group name of group to search for, encoded in UTF-8
+     */
     bool hasGroup(const QByteArray &group) const;
 
     /**
      * Returns an object for the named subgroup.
      *
-     * @param group the group to open. Pass a null string on to the KConfig
+     * @param group the group to open. Pass an empty string here to the KConfig
      *   object to obtain a handle on the root group.
-     * @return The list of groups.
+     * @return config group object for the given group name.
-     **/
+     */
-    KConfigGroup group(const QByteArray &group);
     KConfigGroup group(const QString &group);
+    /**
+     * Overload for group(const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
+    KConfigGroup group(const QByteArray &group);
+    /**
+     * Overload for group(const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
     KConfigGroup group(const char *group);
 
     /**
-     * @overload
+     * Const overload for group(const QString&)
-     **/
+     */
-    const KConfigGroup group(const QByteArray &group) const;
     const KConfigGroup group(const QString &group) const;
+    /**
+     * Const overload for group(const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
+    const KConfigGroup group(const QByteArray &group) const;
+    /**
+     * Const overload for group(const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
     const KConfigGroup group(const char *group) const;
 
     /**
-     * Delete @p aGroup. This marks @p aGroup as @em deleted in the config object. This effectively
+     * Delete @p group.
+     * This marks @p group as @em deleted in the config object. This effectively
      * removes any cascaded values from config files earlier in the stack.
      */
-    void deleteGroup(const QByteArray &group, WriteConfigFlags flags = Normal);
     void deleteGroup(const QString &group, WriteConfigFlags flags = Normal);
+    /**
+     * Overload for deleteGroup(const QString&, WriteConfigFlags)
+     *
+     * @param group name of group to delete, encoded in UTF-8
+     */
+    void deleteGroup(const QByteArray &group, WriteConfigFlags flags = Normal);
+    /**
+     * Overload for deleteGroup(const QString&, WriteConfigFlags)
+     *
+     * @param group name of group to delete, encoded in UTF-8
+     */
     void deleteGroup(const char *group, WriteConfigFlags flags = Normal);
 
     /**
@@ -154,23 +195,38 @@ public:
     virtual bool isImmutable() const = 0;
 
     /**
-     * Can changes be made to the entries in @p aGroup?
+     * Can changes be made to the entries in @p group?
+     *
+     * @param group The group to check for immutability.
+     * @return @c false if the entries in @p group can be modified, otherwise @c true
+     */
+    bool isGroupImmutable(const QString &group) const;
+    /**
+     * Overload for isGroupImmutable(const QString&) const
+     *
+     * @param group name of group, encoded in UTF-8
+     */
+    bool isGroupImmutable(const QByteArray &group) const;
+    /**
+     * Overload for isGroupImmutable(const QString&) const
      *
-     * @param aGroup The group to check for immutability.
+     * @param group name of group, encoded in UTF-8
-     * @return @c false if the entries in @p aGroup can be modified.
      */
-    bool isGroupImmutable(const QByteArray &aGroup) const;
+    bool isGroupImmutable(const char *group) const;
-    bool isGroupImmutable(const QString &aGroup) const;
-    bool isGroupImmutable(const char *aGroup) const;
 
 protected:
     KConfigBase();
 
+    /// @param group name of group, encoded in UTF-8
     virtual bool hasGroupImpl(const QByteArray &group) const = 0;
-    virtual KConfigGroup groupImpl(const QByteArray &b) = 0;
+    /// @param group name of group, encoded in UTF-8
-    virtual const KConfigGroup groupImpl(const QByteArray &b) const = 0;
+    virtual KConfigGroup groupImpl(const QByteArray &group) = 0;
+    /// @param group name of group, encoded in UTF-8
+    virtual const KConfigGroup groupImpl(const QByteArray &group) const = 0;
+    /// @param group name of group, encoded in UTF-8
     virtual void deleteGroupImpl(const QByteArray &group, WriteConfigFlags flags = Normal) = 0;
-    virtual bool isGroupImmutableImpl(const QByteArray &aGroup) const = 0;
+    /// @param group name of group, encoded in UTF-8
+    virtual bool isGroupImmutableImpl(const QByteArray &group) const = 0;
 
     /** Virtual hook, used to add new "virtual" functions while maintaining
      * binary compatibility. Unused in this class.

src/core/kconfiggroup.h

@@ -51,10 +51,14 @@ public:
      * This allows the creation of subgroups by passing another
      * group as @p master.
      *
-     * @p group is the group name encoded in UTF-8.
+     * @param group name of group
      */
     KConfigGroup(KConfigBase *master, const QString &group);
-    /** Overload for KConfigGroup(KConfigBase*,const QString&) */
+    /**
+     * Overload for KConfigGroup(KConfigBase*,const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
     KConfigGroup(KConfigBase *master, const char *group);
 
     /**
@@ -66,12 +70,20 @@ public:
      * as @p master.
      */
     KConfigGroup(const KConfigBase *master, const QString &group);
-    /** Overload for KConfigGroup(const KConfigBase*,const QString&) */
+    /**
+     * Overload for KConfigGroup(const KConfigBase*,const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
     KConfigGroup(const KConfigBase *master, const char *group);
 
     /** Overload for KConfigGroup(const KConfigBase*,const QString&) */
     KConfigGroup(const QExplicitlySharedDataPointer<KSharedConfig> &master, const QString &group);
-    /** Overload for KConfigGroup(const KConfigBase*,const QString&) */
+    /**
+     * Overload for KConfigGroup(const KConfigBase*,const QString&)
+     *
+     * @param group name of group, encoded in UTF-8
+     */
     KConfigGroup(const QExplicitlySharedDataPointer<KSharedConfig> &master, const char *group);
 
     /**
@@ -143,6 +155,8 @@ public:
     /**
      * Overload for changeGroup(const QString&)
      *
+     * @param group name of group, encoded in UTF-8
+     *
      * @deprecated Since 5.0.
      * Create another KConfigGroup from the parent of this group instead.
      */
@@ -237,7 +251,10 @@ public:
     {
         return readEntry(key.toUtf8().constData(), aDefault);
     }
-    /** Overload for readEntry(const QString&, const T&) const */
+    /**
+     * Overload for readEntry<T>(const QString&, const T&) const
+     * @param key name of key, encoded in UTF-8
+     */
     template <typename T>
     T readEntry(const char *key, const T &aDefault) const;
 
@@ -251,7 +268,10 @@ public:
      * @see writeEntry(), deleteEntry(), hasKey()
      */
     QVariant readEntry(const QString &key, const QVariant &aDefault) const;
-    /** Overload for readEntry(const QString&, const QVariant&) */
+    /**
+     * Overload for readEntry(const QString&, const QVariant&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QVariant readEntry(const char *key, const QVariant &aDefault) const;
 
     /**
@@ -266,12 +286,18 @@ public:
      * @see readPathEntry(), writeEntry(), deleteEntry(), hasKey()
      */
     QString readEntry(const QString &key, const QString &aDefault) const;
-    /** Overload for readEntry(const QString&, const QString&) */
+    /**
+     * Overload for readEntry(const QString&, const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QString readEntry(const char *key, const QString &aDefault) const;
 
-    /** Overload for readEntry(const QString&, const QString&) */
+    /** Overload for readEntry(const QString&, const QString&) const */
     QString readEntry(const QString &key, const char *aDefault = nullptr) const;
-    /** Overload for readEntry(const QString&, const QString&) */
+    /**
+     * Overload for readEntry(const QString&, const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QString readEntry(const char *key, const char *aDefault = nullptr) const;
 
     /**
@@ -283,7 +309,10 @@ public:
      *          readEntry(const char*, const QList<T>&) const
      */
     QVariantList readEntry(const QString &key, const QVariantList &aDefault) const;
-    /** Overload for readEntry(const QString&, const QVariantList&) */
+    /**
+     * Overload for readEntry(const QString&, const QVariantList&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QVariantList readEntry(const char *key, const QVariantList &aDefault) const;
 
     /**
@@ -296,7 +325,10 @@ public:
      * @see readXdgListEntry(), writeEntry(), deleteEntry(), hasKey()
      */
     QStringList readEntry(const QString &key, const QStringList &aDefault) const;
-    /** Overload for readEntry(const QString&, const QStringList&) */
+    /**
+     * Overload for readEntry(const QString&, const QStringList&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QStringList readEntry(const char *key, const QStringList &aDefault) const;
 
     /**
@@ -313,7 +345,10 @@ public:
     {
         return readEntry(key.toUtf8().constData(), aDefault);
     }
-    /** Overload for readEntry(const QString&, const QList<T>&) */
+    /**
+     * Overload for readEntry<T>(const QString&, const QList<T>&) const
+     * @param key name of key, encoded in UTF-8
+     */
     template<typename T>
     QList<T> readEntry(const char *key, const QList<T> &aDefault) const;
 
@@ -328,8 +363,11 @@ public:
      * @see readEntry(const QString&, const QStringList&) const
      */
     QStringList readXdgListEntry(const QString &pKey, const QStringList &aDefault = QStringList()) const;
-    /** Overload for readXdgListEntry(const QString&, const QStringList&) */
+    /**
-    QStringList readXdgListEntry(const char *pKey, const QStringList &aDefault = QStringList()) const;
+     * Overload for readXdgListEntry(const QString&, const QStringList&) const
+     * @param key name of key, encoded in UTF-8
+     */
+    QStringList readXdgListEntry(const char *key, const QStringList &aDefault = QStringList()) const;
 
     /**
      * Reads a path
@@ -343,7 +381,10 @@ public:
      * @return The value for this key. Can be QString() if @p aDefault is null.
      */
     QString readPathEntry(const QString &pKey, const QString &aDefault) const;
-    /** Overload for readPathEntry(const QString&, const QString&) */
+    /**
+     * Overload for readPathEntry(const QString&, const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QString readPathEntry(const char *key, const QString &aDefault) const;
 
     /**
@@ -358,7 +399,10 @@ public:
      * @return the list, or @p aDefault if the key does not exist
      */
     QStringList readPathEntry(const QString &pKey, const QStringList &aDefault) const;
-    /** Overload for readPathEntry(const QString&, const QStringList&) */
+    /**
+     * Overload for readPathEntry(const QString&, const QStringList&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QStringList readPathEntry(const char *key, const QStringList &aDefault) const;
 
     /**
@@ -372,7 +416,10 @@ public:
      */
     QString readEntryUntranslated(const QString &pKey,
                                   const QString &aDefault = QString()) const;
-    /** Overload for readEntryUntranslated(const QString&, const QString&) */
+    /**
+     * Overload for readEntryUntranslated(const QString&, const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     QString readEntryUntranslated(const char *key,
                                   const QString &aDefault = QString()) const;
 
@@ -387,30 +434,45 @@ public:
      */
     void writeEntry(const QString &key, const QVariant &value,
                     WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const QVariant &value,
                     WriteConfigFlags pFlags = Normal);
 
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
     void writeEntry(const QString &key, const QString &value,
                     WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const QString &value,
                     WriteConfigFlags pFlags = Normal);
 
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
     void writeEntry(const QString &key, const QByteArray &value,
                     WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const QByteArray &value,
                     WriteConfigFlags pFlags = Normal);
 
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
     void writeEntry(const QString &key, const char *value, WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const char *value, WriteConfigFlags pFlags = Normal);
 
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     template <typename T>
     void writeEntry(const char *key, const T &value, WriteConfigFlags pFlags = Normal);
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
@@ -423,14 +485,20 @@ public:
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
     void writeEntry(const QString &key, const QStringList &value,
                     WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const QStringList &value,
                     WriteConfigFlags pFlags = Normal);
 
     /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
     void writeEntry(const QString &key, const QVariantList &value,
                     WriteConfigFlags pFlags = Normal);
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void writeEntry(const char *key, const QVariantList &value,
                     WriteConfigFlags pFlags = Normal);
 
@@ -440,7 +508,10 @@ public:
     {
         writeEntry(key.toUtf8().constData(), value, pFlags);
     }
-    /** Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags) */
+    /**
+     * Overload for writeEntry(const QString&, const QVariant&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     template <typename T>
     void writeEntry(const char *key, const QList<T> &value, WriteConfigFlags pFlags = Normal);
 
@@ -456,8 +527,11 @@ public:
      */
     void writeXdgListEntry(const QString &pKey, const QStringList &value,
                            WriteConfigFlags pFlags = Normal);
-    /** Overload for writeXdgListEntry(const QString&, const QStringList&, WriteConfigFlags) */
+    /**
-    void writeXdgListEntry(const char *pKey, const QStringList &value,
+     * Overload for writeXdgListEntry(const QString&, const QStringList&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
+    void writeXdgListEntry(const char *key, const QStringList &value,
                            WriteConfigFlags pFlags = Normal);
 
     /**
@@ -475,8 +549,11 @@ public:
      */
     void writePathEntry(const QString &pKey, const QString &path,
                         WriteConfigFlags pFlags = Normal);
-    /** Overload for writePathEntry(const QString&, const QString&, WriteConfigFlags) */
+    /**
-    void writePathEntry(const char *pKey, const QString &path,
+     * Overload for writePathEntry(const QString&, const QString&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
+    void writePathEntry(const char *Key, const QString &path,
                         WriteConfigFlags pFlags = Normal);
 
     /**
@@ -494,8 +571,11 @@ public:
      */
     void writePathEntry(const QString &pKey, const QStringList &value,
                         WriteConfigFlags pFlags = Normal);
-    /** Overload for writePathEntry(const QString&, const QStringList&, WriteConfigFlags) */
+    /**
-    void writePathEntry(const char *pKey, const QStringList &value,
+     * Overload for writePathEntry(const QString&, const QStringList&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
+    void writePathEntry(const char *key, const QStringList &value,
                         WriteConfigFlags pFlags = Normal);
 
     /**
@@ -509,8 +589,11 @@ public:
      * @see deleteGroup(), readEntry(), writeEntry()
      */
     void deleteEntry(const QString &pKey, WriteConfigFlags pFlags = Normal);
-    /** Overload for deleteEntry(const QString&, WriteConfigFlags) */
+    /**
-    void deleteEntry(const char *pKey, WriteConfigFlags pFlags = Normal);
+     * Overload for deleteEntry(const QString&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
+    void deleteEntry(const char *key, WriteConfigFlags pFlags = Normal);
 
     /**
      * Checks whether the key has an entry in this group
@@ -528,7 +611,10 @@ public:
      * @see readEntry()
      */
     bool hasKey(const QString &key) const;
-    /** Overload for hasKey(const QString&) const */
+    /**
+     * Overload for hasKey(const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     bool hasKey(const char *key) const;
 
     /**
@@ -549,7 +635,10 @@ public:
      *         group object, @c true otherwise
      */
     bool isEntryImmutable(const QString &key) const;
-    /** Overload for isEntryImmutable(const QString&) const */
+    /**
+     * Overload for isEntryImmutable(const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     bool isEntryImmutable(const char *key) const;
 
     /**
@@ -572,9 +661,16 @@ public:
     void revertToDefault(const QString &key);
     void revertToDefault(const QString &key, WriteConfigFlags pFlag);
 
-    /** Overload for revertToDefault(const QString&) */
     // TODO KF6 merge with the other one
+    /**
+     * Overload for revertToDefault(const QString&)
+     * @param key name of key, encoded in UTF-8
+     */
     void revertToDefault(const char *key);
+    /**
+     * Overload for revertToDefault(const QString&, WriteConfigFlags)
+     * @param key name of key, encoded in UTF-8
+     */
     void revertToDefault(const char *key, WriteConfigFlags pFlag);
 
     /**
@@ -605,7 +701,10 @@ public:
      *          for @p key in this group, @c false otherwise
      */
     bool hasDefault(const QString &key) const;
-    /** Overload for hasDefault(const QString&) const */
+    /**
+     * Overload for hasDefault(const QString&) const
+     * @param key name of key, encoded in UTF-8
+     */
     bool hasDefault(const char *key) const;
 
     /**

src/core/kconfigwatcher.h

@@ -50,7 +50,7 @@ Q_SIGNALS:
      * The config will be reloaded before this signal is emitted
      *
      * @arg group the config group that has changed
-     * @arg names a list of entries that have changed within that group
+     * @arg names a list of entries that have changed within that group (UTF-8 encoded)
      */
     void configChanged(const KConfigGroup &group, const QByteArrayList &names);