Add changelog2appdata into cmake build

Telegram/CMakeLists.txt

@@ -33,6 +33,7 @@ include(cmake/td_mtproto.cmake)
 include(cmake/td_lang.cmake)
 include(cmake/td_scheme.cmake)
 include(cmake/td_ui.cmake)
+include(cmake/generate_appdata_changelog.cmake)
 
 set_target_properties(Telegram PROPERTIES AUTOMOC ON AUTORCC ON)
 
@@ -1319,6 +1320,7 @@ endif()
 if (LINUX AND DESKTOP_APP_USE_PACKAGED)
     include(GNUInstallDirs)
     configure_file("../lib/xdg/telegramdesktop.appdata.xml.in" "${CMAKE_CURRENT_BINARY_DIR}/telegramdesktop.appdata.xml" @ONLY)
+    generate_appdata_changelog(Telegram "../changelog.txt" "${CMAKE_CURRENT_BINARY_DIR}/telegramdesktop.appdata.xml")
     install(TARGETS Telegram RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" BUNDLE DESTINATION "${CMAKE_INSTALL_BINDIR}")
     install(FILES "Resources/art/icon16.png" DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/icons/hicolor/16x16/apps" RENAME "telegram.png")
     install(FILES "Resources/art/icon32.png" DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/icons/hicolor/32x32/apps" RENAME "telegram.png")

Telegram/cmake/generate_appdata_changelog.cmake

@@ -0,0 +1,24 @@
+# This file is part of Telegram Desktop,
+# the official desktop application for the Telegram messaging service.
+#
+# For license and copyright information please follow this link:
+# https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+
+function(generate_appdata_changelog target_name changelog_path appdata_path)
+    find_package(Python3 REQUIRED)
+
+    add_custom_target(${target_name}_appdata_changelog
+        ${Python3_EXECUTABLE}
+        ${submodules_loc}/build/changelog2appdata.py
+        -c "${changelog_path}"
+        -a "${appdata_path}"
+        -n 10
+    COMMENT "Generating AppData changelog (${target_name})"
+    DEPENDS
+        ${submodules_loc}/build/changelog2appdata.py
+        ${changelog_path}
+        ${appdata_path}
+    VERBATIM
+    )
+    add_dependencies(${target_name} ${target_name}_appdata_changelog)
+endfunction()