Prevent wrong data directory selection.

Validate data directory by checking for known file.

Issue #189.

CMakeLists.txt

@@ -53,6 +53,9 @@ function(set_compile_options target)
 			target_compile_options(${target} PRIVATE -Werror)
 		endif()
 	endif()
+	if (DEV_BUILD)
+		target_compile_definitions(${target} PRIVATE GPICK_DEV_BUILD)
+	endif()
 endfunction()
 
 function(add_gtk_options target)
@@ -203,7 +206,7 @@ install(FILES share/applications/gpick.desktop DESTINATION share/applications)
 install(FILES share/mime/packages/gpick.xml DESTINATION share/mime/packages)
 install(FILES share/doc/gpick/copyright DESTINATION share/doc/gpick)
 install(FILES share/man/man1/gpick.1 DESTINATION share/man/man1)
-file(GLOB RESOURCE_FILES share/gpick/*.png share/gpick/*.lua share/gpick/*.txt)
+file(GLOB RESOURCE_FILES share/gpick/*.png share/gpick/*.lua share/gpick/*.txt share/gpick/.gpick-data-directory)
 install(FILES ${RESOURCE_FILES} DESTINATION share/gpick)
 install(DIRECTORY share/icons DESTINATION share)
 if (ENABLE_NLS)

SConscript

@@ -143,6 +143,9 @@ else:
 				LINKFLAGS = ['/MANIFEST', '/LTCG'],
 			)
 
+if env['DEV_BUILD']:
+	env.Append(CPPDEFINES = ['GPICK_DEV_BUILD'])
+
 env.Append(CPPPATH = ['#source'])
 
 def buildVersion(env):
@@ -369,7 +372,7 @@ env.Alias(target = "install", source = [
 	env.InstallData(dir = env['DESTDIR'] +'/share/applications', source = ['share/applications/gpick.desktop']),
 	env.InstallData(dir = env['DESTDIR'] +'/share/mime/packages', source = ['share/mime/packages/gpick.xml']),
 	env.InstallData(dir = env['DESTDIR'] +'/share/doc/gpick', source = ['share/doc/gpick/copyright']),
-	env.InstallData(dir = env['DESTDIR'] +'/share/gpick', source = [env.Glob('share/gpick/*.png'), env.Glob('share/gpick/*.lua'), env.Glob('share/gpick/*.txt')]),
+	env.InstallData(dir = env['DESTDIR'] +'/share/gpick', source = [env.Glob('share/gpick/*.png'), env.Glob('share/gpick/*.lua'), env.Glob('share/gpick/*.txt'), env.Glob('share/gpick/.gpick-data-directory')]),
 	env.InstallData(dir = env['DESTDIR'] +'/share/man/man1', source = ['share/man/man1/gpick.1']),
 	env.InstallData(dir = env['DESTDIR'] +'/share/icons/hicolor/48x48/apps/', source = [env.Glob('share/icons/hicolor/48x48/apps/*.png')]),
 	env.InstallData(dir = env['DESTDIR'] +'/share/icons/hicolor/scalable/apps/', source = [env.Glob('share/icons/hicolor/scalable/apps/*.svg')]),

source/Paths.cpp

@@ -24,7 +24,7 @@
 #include <exception>
 namespace fs = boost::filesystem;
 using path = fs::path;
-struct PathException : std::runtime_error {
+struct PathException: std::runtime_error {
 	PathException(const char *message):
 		std::runtime_error(message) {
 	}
@@ -54,23 +54,55 @@ static path &getUserConfigPath() {
 	configPath = path(g_get_user_config_dir());
 	return *configPath;
 }
+static bool validateDataPath(const path &path) {
+	try {
+		if (!fs::is_directory(fs::status(path)))
+			return false;
+		if (!fs::is_regular_file(fs::status(path / ".gpick-data-directory")))
+			return false;
+		return true;
+	} catch (const fs::filesystem_error &) {
+		return false;
+	}
+}
+static bool getRelativeDataPath(boost::optional<path> &dataPath) {
+	try {
+		path testPath;
+		if (validateDataPath(testPath = (path(getExecutablePath()).remove_filename() / "share" / "gpick"))) {
+			dataPath = testPath;
+			return true;
+		}
+		if (validateDataPath(testPath = (path(getExecutablePath()).remove_filename().remove_filename() / "share" / "gpick"))) {
+			dataPath = testPath;
+			return true;
+		}
+		return false;
+	} catch (const PathException &) {
+		return false;
+	} catch (const fs::filesystem_error &) {
+		return false;
+	}
+}
 static path &getDataPath() {
 	static boost::optional<path> dataPath;
 	if (dataPath)
 		return *dataPath;
 	path testPath;
-	try {
-		if (fs::is_directory(fs::status(testPath = (path(getExecutablePath()).remove_filename() / "share" / "gpick"))))
-			return *(dataPath = testPath);
-	} catch (const PathException &) {
-	}
-	if (fs::is_directory(fs::status(testPath = (path(g_get_user_data_dir()) / "gpick"))))
+#ifdef GPICK_DEV_BUILD
+	if (getRelativeDataPath(dataPath))
+		return *dataPath;
+#endif
+	if (validateDataPath(testPath = (path(g_get_user_data_dir()) / "gpick")))
 		return *(dataPath = testPath);
 	auto dataPaths = g_get_system_data_dirs();
 	for (size_t i = 0; dataPaths[i]; ++i) {
-		if (fs::is_directory(fs::status(testPath = (path(dataPaths[i]) / "gpick"))))
+		if (validateDataPath(testPath = (path(dataPaths[i]) / "gpick")))
 			return *(dataPath = testPath);
 	}
+#ifndef GPICK_DEV_BUILD
+	if (getRelativeDataPath(dataPath))
+		return *dataPath;
+#endif
 	dataPath = path();
 	return *dataPath;
 }