diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9cef39b2..1bfe44a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,200 +1,204 @@
 cmake_minimum_required(VERSION 3.7.2)
 
 if(POLICY CMP0048)
     cmake_policy(SET CMP0048 NEW)
 endif(POLICY CMP0048)
 
 project(
     kbibtex
     VERSION 0.9.50
     LANGUAGES CXX
 )
 
 set(CMAKE_CXX_STANDARD 11)
 set(QT_MIN_VERSION 5.9.0)
 # Somewhat arbitrary chosen version number ...
 set(KF5_MIN_VERSION 5.51)
 find_package(ECM ${KF5_MIN_VERSION} REQUIRED NO_MODULE)
 
 set(
     CMAKE_MODULE_PATH
     ${ECM_MODULE_PATH}
     ${ECM_KDE_MODULE_DIR}
     ${CMAKE_MODULE_PATH}
 )
 
 set(KDE_INSTALL_DIRS_NO_DEPRECATED TRUE)
 include(KDEInstallDirs)
 include(KDECompilerSettings NO_POLICY_SCOPE)
 include(KDECMakeSettings)
 include(ECMGenerateHeaders)
 include(ECMInstallIcons)
 include(ECMSetupVersion)
 include(ECMAddAppIcon)
 include(GenerateExportHeader)
 include(ECMQtDeclareLoggingCategory)
 
 ecm_setup_version(
     PROJECT
     VARIABLE_PREFIX KBIBTEX
     SOVERSION ${KBIBTEX_VERSION_MAJOR}
     VERSION_HEADER "${CMAKE_BINARY_DIR}/kbibtex-version.h"
     PACKAGE_VERSION_FILE "${CMAKE_BINARY_DIR}/KBibTeXConfigVersion.cmake"
 )
 
 install(
     FILES ${CMAKE_BINARY_DIR}/kbibtex-version.h
     DESTINATION ${KDE_INSTALL_INCLUDEDIR}/KBibTeX
     # FIXME is "Devel" standard?
     COMPONENT Devel
 )
 
 
 if("${KBIBTEX_VERSION_PATCH}" STREQUAL "")
     # Patch level is not set for version numbers like "0.9",
     # so set the patch level manually to 0
     set(KBIBTEX_VERSION_PATCH 0)
 endif()
 
 if((${KBIBTEX_VERSION_PATCH} GREATER 50) OR (${KBIBTEX_VERSION_PATCH} EQUAL 50))
     # If the version number indicates a pre-release version such as
     # '0.7.90', i.e. a beta version for the major release 0.8,
     # increment release version from 0.7 to 0.8
     math(EXPR KBIBTEX_RELEASE_VERSION_MINOR "${KBIBTEX_VERSION_MINOR} + 1")
     set(
         KBIBTEX_RELEASE_VERSION ${KBIBTEX_VERSION_MAJOR}.${KBIBTEX_RELEASE_VERSION_MINOR}
     )
 else()
     set(
         KBIBTEX_RELEASE_VERSION ${KBIBTEX_VERSION_MAJOR}.${KBIBTEX_VERSION_MINOR}
     )
 endif()
 
 option(
     UNITY_BUILD
     "Compile multiple C++ files in one big, merged file (\"Unity build\")\nSee also https://t-fischer.dreamwidth.org/3054.html"
 )
 if(UNITY_BUILD)
     message(STATUS "Unity build enabled")
 else(UNITY_BUILD)
     message(STATUS "Unity build disabled (default), use option UNITY_BUILD to enable it")
 endif(UNITY_BUILD)
 
 find_package(
     Qt5 ${QT_MIN_VERSION}
     CONFIG
     COMPONENTS
     Core
     Widgets
     Network
     XmlPatterns
     Concurrent
     NetworkAuth
     OPTIONAL_COMPONENTS
     WebEngineWidgets
     WebKitWidgets
     Test
 )
 add_definitions(-DHAVE_QTWIDGETS)
 
 find_package(
     KF5 ${KF5_MIN_VERSION}
     MODULE
     REQUIRED
     I18n
     XmlGui
     KIO
     IconThemes
     Parts
     CoreAddons
     Service
     Wallet
     Crash
     DocTools
     TextEditor
 )
 add_definitions(-DHAVE_KF5)
 
 find_package(
     Poppler
     MODULE
     REQUIRED
     Qt5
 )
 
 find_package(
     ICU
     MODULE
     OPTIONAL_COMPONENTS
     uc i18n
 )
 if(ICU_FOUND)
     add_definitions(-DHAVE_ICU)
 endif()
 
 option(
     BUILD_TESTING
     "Build automated and interactive tests"
     OFF
 )
 if (MSVC)
     MESSAGE( STATUS "Disabling building tests when using Microsoft Visual Studio C++ compiler" )
     # Note to any developer: Try to enable building tests and see which issues you may encounter.
     # Examples may include: (1) char* texts which exceed the size limit supported by MSVC which
     # is about 2^16 bytes and (2) characters in strings written in \uXXXX notation not supported
     # in 1252 encoding as assumed by MSVC for C++ source files.
     set(BUILD_TESTING OFF)
 endif()
 if(NOT BUILD_TESTING AND Qt5Test_FOUND)
     message(STATUS
         "Testing is disabled, but can be enabled as the Qt5::Test library is available"
     )
 endif()
 if(BUILD_TESTING AND NOT Qt5Test_FOUND)
     message(STATUS
         "Disabling building tests as Qt5::Test library is not available"
     )
     set(BUILD_TESTING OFF)
 endif()
 
 if(BUILD_TESTING)
     if (WRITE_RAWDATAFILE)
         add_definitions(-DWRITE_RAWDATAFILE)
     endif(WRITE_RAWDATAFILE)
 
     set(
         TESTSET_DIRECTORY ""
         CACHE PATH
         "Directory where the local checkout of Git repository 'kbibtex-testset' is located"
     )
 endif()
 
-
+if(TESTSET_DIRECTORY AND ( NOT EXISTS "${TESTSET_DIRECTORY}/bib/minix.bib" OR NOT EXISTS "${TESTSET_DIRECTORY}/bib/backslash.bib" ))
+    message("Variable TESTSET_DIRECTORY is set to '${TESTSET_DIRECTORY}' but various BibTeX files were not found. Unsetting TESTSET_DIRECTORY.")
+    unset(TESTSET_DIRECTORY)
+    unset(TESTSET_DIRECTORY CACHE)
+endif()
 
 
 add_subdirectory(
     config
 )
 add_subdirectory(
     src
 )
 add_subdirectory(
     xslt
 )
 add_subdirectory(
     mime
 )
 if(KF5DocTools_FOUND)
     add_subdirectory(doc)
 endif()
 # macro_optional_add_subdirectory(
 #     po
 # )
 
 if (ECM_VERSION VERSION_GREATER_EQUAL "5.59.0")
     install(FILES kbibtex.categories DESTINATION ${KDE_INSTALL_LOGGINGCATEGORIESDIR})
 else()
     install(FILES kbibtex.categories DESTINATION ${KDE_INSTALL_CONFDIR})
 endif()
 
 feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index 8677f3ac..72463e0a 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -1,201 +1,202 @@
 include(AddFileDependencies)
 include(ECMMarkAsTest)
 
 configure_file(test-config.h.in test-config.h @ONLY)
 
 set(
     kbibtextest_SRCS
     main.cpp
     kbibtextest.cpp
 )
 
 ecm_qt_declare_logging_category(kbibtextest_SRCS
     HEADER logging_test.h
     IDENTIFIER LOG_KBIBTEX_TEST
     CATEGORY_NAME kbibtex.test
 )
 
-set(
-    kbibtexfilestest_SRCS
-    kbibtexfilestest.cpp
-    kbibtexfilestest-rawdata.h
-)
-
-ecm_qt_declare_logging_category(kbibtexfilestest_SRCS
-    HEADER logging_test.h
-    IDENTIFIER LOG_KBIBTEX_TEST
-    CATEGORY_NAME kbibtex.test
-)
 
 set(
     kbibtexnetworkingtest_SRCS
     kbibtexnetworkingtest.cpp
 )
 
 set(
     kbibtexiotest_SRCS
     kbibtexiotest.cpp
 )
 
 ecm_qt_declare_logging_category(kbibtexiotest_SRCS
     HEADER logging_test.h
     IDENTIFIER LOG_KBIBTEX_TEST
     CATEGORY_NAME kbibtex.test
 )
 
 set(
     kbibtexdatatest_SRCS
     kbibtexdatatest.cpp
 )
 
 if(UNITY_BUILD AND NOT WIN32) # FIXME: Unity build of programs breaks on Windows
     enable_unity_build(kbibtextest kbibtextest_SRCS)
-    enable_unity_build(kbibtexfilestest kbibtexfilestest_SRCS)
     enable_unity_build(kbibtexnetworkingtest kbibtexnetworkingtest_SRCS)
     enable_unity_build(kbibtexiotest kbibtexiotest_SRCS)
     enable_unity_build(kbibtexdatatest kbibtexdatatest_SRCS)
 endif(UNITY_BUILD AND NOT WIN32)
 
 add_executable(
     kbibtextest
     ${kbibtextest_SRCS}
 )
 
 add_dependencies(kbibtextest
     generate-kbibtex-git-info
 )
 
-add_executable(
-    kbibtexfilestest
-    ${kbibtexfilestest_SRCS}
-)
-
-add_dependencies(kbibtexfilestest
-    generate-kbibtex-git-info
-)
-
 add_executable(
     kbibtexnetworkingtest
     ${kbibtexnetworkingtest_SRCS}
 )
 
 add_dependencies(kbibtexnetworkingtest
     generate-kbibtex-git-info
 )
 
 add_executable(
     kbibtexiotest
     ${kbibtexiotest_SRCS}
 )
 
 add_dependencies(kbibtexiotest
     generate-kbibtex-git-info
 )
 
 add_executable(
     kbibtexdatatest
     ${kbibtexdatatest_SRCS}
 )
 
 add_dependencies(kbibtexdatatest
     generate-kbibtex-git-info
 )
 
 target_link_libraries(kbibtextest
     Qt5::Core
     KF5::KIOCore
     KF5::I18n
     KBibTeX::Config
     KBibTeX::Data
     KBibTeX::IO
     KBibTeX::Processing
     KBibTeX::GUI
     KBibTeX::Networking
 )
 
 target_include_directories(kbibtextest
     PRIVATE
         ${CMAKE_BINARY_DIR}
 )
 
-target_link_libraries(kbibtexfilestest
-    PRIVATE
-        Qt5::Test
-        KBibTeX::Data
-        KBibTeX::IO
-)
-
-target_include_directories(kbibtexfilestest
-    PRIVATE
-        ${CMAKE_BINARY_DIR}
-)
-
 target_link_libraries(kbibtexnetworkingtest
     PRIVATE
         Qt5::Test
         KBibTeX::Networking
 )
 
 target_include_directories(kbibtexnetworkingtest
     PRIVATE
         ${CMAKE_BINARY_DIR}
 )
 
 target_link_libraries(kbibtexiotest
     PRIVATE
         Qt5::Test
         KF5::I18n
         KF5::ConfigCore
         KBibTeX::IO
 )
 
 target_include_directories(kbibtexiotest
     PRIVATE
         ${CMAKE_BINARY_DIR}
 )
 
 target_link_libraries(kbibtexdatatest
     PRIVATE
         Qt5::Test
         KBibTeX::Data
 )
 
 target_include_directories(kbibtexdatatest
     PRIVATE
         ${CMAKE_BINARY_DIR}
 )
 
 ecm_mark_as_test(
-    kbibtexfilestest
     kbibtexnetworkingtest
     kbibtexiotest
     kbibtexdatatest
 )
 
-add_test(
-    NAME
-    kbibtexfilestest
-    COMMAND
-    kbibtexfilestest
-)
-
 add_test(
     NAME
     kbibtexnetworkingtest
     COMMAND
     kbibtexnetworkingtest
 )
 
 add_test(
     NAME
     kbibtexiotest
     COMMAND
     kbibtexiotest
 )
 
 add_test(
     NAME
     kbibtexdatatest
     COMMAND
     kbibtexdatatest
 )
+
+if(TESTSET_DIRECTORY)
+    set(
+        kbibtexfilestest_SRCS
+        kbibtexfilestest.cpp
+        kbibtexfilestest-rawdata.h
+    )
+    ecm_qt_declare_logging_category(kbibtexfilestest_SRCS
+        HEADER logging_test.h
+        IDENTIFIER LOG_KBIBTEX_TEST
+        CATEGORY_NAME kbibtex.test
+    )
+    if(UNITY_BUILD AND NOT WIN32) # FIXME: Unity build of programs breaks on Windows
+        enable_unity_build(kbibtexfilestest kbibtexfilestest_SRCS)
+    endif()
+    add_executable(
+        kbibtexfilestest
+        ${kbibtexfilestest_SRCS}
+    )
+    add_dependencies(kbibtexfilestest
+        generate-kbibtex-git-info
+    )
+    target_link_libraries(kbibtexfilestest
+        PRIVATE
+            Qt5::Test
+            KBibTeX::Data
+            KBibTeX::IO
+    )
+    target_include_directories(kbibtexfilestest
+        PRIVATE
+            ${CMAKE_BINARY_DIR}
+    )
+    ecm_mark_as_test(
+        kbibtexfilestest
+    )
+    add_test(
+        NAME
+        kbibtexfilestest
+        COMMAND
+        kbibtexfilestest
+    )
+endif()