Add KF6/Qt6 build support with auto-detection

CMakeLists.txt now probes for KF6TextEditor first, falls back to KF5.
Uses correct install namespace (kf6/ktexteditor vs ktexteditor).
Source code already had the necessary #if guards for KF6 constructor.
No API changes needed - KTextEditor plugin interface is identical.

CMakeLists.txt

@@ -5,30 +5,55 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_AUTOMOC ON)
 
-find_package(ECM REQUIRED NO_MODULE)
+find_package(ECM 5.80 REQUIRED NO_MODULE)
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH})
 
+# Probe for KF6 before including KDE macros (which need QT_MAJOR_VERSION)
+find_package(KF6TextEditor QUIET CONFIG)
+if(KF6TextEditor_FOUND)
+    set(QT_MAJOR_VERSION 6)
+else()
+    set(QT_MAJOR_VERSION 5)
+endif()
+
 include(KDEInstallDirs)
 include(KDECMakeSettings)
 include(KDECompilerSettings NO_POLICY_SCOPE)
 
-find_package(Qt5 REQUIRED COMPONENTS Core Widgets)
-find_package(KF5TextEditor REQUIRED)
-find_package(KF5I18n REQUIRED)
-find_package(KF5CoreAddons REQUIRED)
+if(QT_MAJOR_VERSION EQUAL 6)
+    find_package(Qt6 REQUIRED COMPONENTS Core Widgets)
+    find_package(KF6I18n REQUIRED)
+    find_package(KF6CoreAddons REQUIRED)
+    set(KF_LINK_LIBS
+        KF6::TextEditor
+        KF6::I18n
+        Qt6::Core
+        Qt6::Widgets
+    )
+    set(PLUGIN_INSTALL_NS "kf6/ktexteditor")
+    message(STATUS "Building Git++ with KF6/Qt6")
+else()
+    find_package(Qt5 REQUIRED COMPONENTS Core Widgets)
+    find_package(KF5TextEditor REQUIRED)
+    find_package(KF5I18n REQUIRED)
+    find_package(KF5CoreAddons REQUIRED)
+    set(KF_LINK_LIBS
+        KF5::TextEditor
+        KF5::I18n
+        Qt5::Core
+        Qt5::Widgets
+    )
+    set(PLUGIN_INSTALL_NS "ktexteditor")
+    message(STATUS "Building Git++ with KF5/Qt5")
+endif()
 
 kcoreaddons_add_plugin(gitplusplus
     SOURCES
         gitplusplus.cpp
         gitstatusmodel.cpp
-    INSTALL_NAMESPACE "ktexteditor"
+    INSTALL_NAMESPACE "${PLUGIN_INSTALL_NS}"
 )
 
-target_link_libraries(gitplusplus
-    KF5::TextEditor
-    KF5::I18n
-    Qt5::Core
-    Qt5::Widgets
-)
+target_link_libraries(gitplusplus ${KF_LINK_LIBS})
 
 target_include_directories(gitplusplus PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})

Makefile

@@ -2,11 +2,12 @@
 
 BUILD_DIR := build
 
-all: $(BUILD_DIR)/gitplusplus.so
+all: $(BUILD_DIR)/Makefile
+	@cd $(BUILD_DIR) && make -j$$(nproc)
 
-$(BUILD_DIR)/gitplusplus.so: gitplusplus.cpp gitplusplus.h gitprocess.h gitstatusmodel.cpp gitstatusmodel.h metadata.json
+$(BUILD_DIR)/Makefile: CMakeLists.txt
 	@mkdir -p $(BUILD_DIR)
-	@cd $(BUILD_DIR) && cmake .. -DCMAKE_INSTALL_PREFIX=/usr -Wno-dev 2>/dev/null && make -j$$(nproc)
+	@cd $(BUILD_DIR) && cmake .. -DCMAKE_INSTALL_PREFIX=/usr -Wno-dev
 
 install: all
 	cd $(BUILD_DIR) && sudo make install

README.md

@@ -105,7 +105,13 @@ for file listing, so the file tree shows exactly what git tracks.
 
 ## Building
 
-Requires KF5 (or KF6) development packages:
+Supports both KF5 (Kate on Qt5) and KF6 (Kate on Qt6). The build system
+auto-detects which framework is available, preferring KF6.
+
+**Dependencies** (install the set matching your Kate version):
+
+- KF6: `libkf6texteditor-dev`, `libkf6i18n-dev`, `libkf6coreaddons-dev`, `qt6-base-dev`, `extra-cmake-modules`
+- KF5: `libkf5texteditor-dev`, `libkf5i18n-dev`, `libkf5coreaddons-dev`, `qtbase5-dev`, `extra-cmake-modules`
 
 ```sh
 mkdir build && cd build
@@ -123,9 +129,11 @@ make install
 ## Installation Path
 
 The plugin installs to Kate's KTextEditor plugin directory:
-```
-/usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/gitplusplus.so
-```
+
+- KF6: `/usr/lib64/qt6/plugins/kf6/ktexteditor/gitplusplus.so`
+- KF5: `/usr/lib/x86_64-linux-gnu/qt5/plugins/ktexteditor/gitplusplus.so`
+
+The exact path depends on your distribution's library layout.
 
 Enable it in Kate → Settings → Configure Kate → Plugins → "Git++".