[3party] Do not use jansson from the system to avoid conflicts with protobuf and Qt

Signed-off-by: Alexander Borsuk <me@alex.bio>

CMakeLists.txt

@@ -323,14 +323,13 @@ else()
   add_subdirectory(3party/icu)
 endif()
 
-set(JANSSON_EXAMPLES OFF)
 set(JANSSON_BUILD_DOCS OFF)
-set(JANSSON_WITHOUT_TESTS ON)
+set(JANSSON_BUILD_MAN OFF)
+set(JANSSON_EXAMPLES OFF)
 set(JANSSON_INSTALL OFF)
+set(JANSSON_WITHOUT_TESTS ON)
 find_package_or_fallback_to_3party(Jansson 2.14.0 3party/jansson/jansson/)
-if (NOT Jansson_FOUND)
-  include_directories("${PROJECT_BINARY_DIR}/3party/jansson/jansson/include")
-endif()
+target_include_directories(jansson INTERFACE "${PROJECT_BINARY_DIR}/3party/jansson/jansson/include")
 
 add_subdirectory(3party/liboauthcpp)
 add_subdirectory(3party/minizip)

cmake/FindJansson.cmake

@@ -1,14 +1,18 @@
-if (Jansson_INCLUDE_DIRS AND Jansson_LIBRARY AND Jansson_VERSION)
-  set(Jansson_FOUND TRUE)
-else ()
-  find_path(Jansson_INCLUDE_DIRS NAMES jansson.h)
-  find_library(Jansson_LIBRARY NAMES jansson)
+# This code is commented because it is flawed now. If any system-wide include directory will be added for jannsson,
+# and it will contain wrong versions of protobuf or Qt, the build will fail.
+# And it is not trivial for contributors to find the root cause of such build failure.
 
-  if (Jansson_INCLUDE_DIRS AND Jansson_LIBRARY)
-    set(regex_jansson_version "#define[ \t]+JANSSON_VERSION[ \t]+[\"]([^\"]+)[\"]")
-    file(STRINGS "${Jansson_INCLUDE_DIRS}/jansson.h" Jansson_VERSION REGEX "${regex_jansson_version}")
-    string(REGEX REPLACE "${regex_jansson_version}" "\\1" Jansson_VERSION "${Jansson_VERSION}")
-    unset(regex_jansson_version)
-    set(Jansson_FOUND TRUE)
-  endif ()
-endif()
+#if (Jansson_INCLUDE_DIRS AND Jansson_LIBRARY AND Jansson_VERSION)
+#  set(Jansson_FOUND TRUE)
+#else ()
+#  find_path(Jansson_INCLUDE_DIRS NAMES jansson.h)
+#  find_library(Jansson_LIBRARY NAMES jansson)
+
+#  if (Jansson_INCLUDE_DIRS AND Jansson_LIBRARY)
+#    set(regex_jansson_version "#define[ \t]+JANSSON_VERSION[ \t]+[\"]([^\"]+)[\"]")
+#    file(STRINGS "${Jansson_INCLUDE_DIRS}/jansson.h" Jansson_VERSION REGEX "${regex_jansson_version}")
+#    string(REGEX REPLACE "${regex_jansson_version}" "\\1" Jansson_VERSION "${Jansson_VERSION}")
+#    unset(regex_jansson_version)
+#    set(Jansson_FOUND TRUE)
+#  endif ()
+#endif()