FindCurses: Add option for ncursesw detection

This is a remake of the patch from issue #10347 but based on current
master. Works for me on Lubuntu 17.04.

Fixes: #10347

Modules/FindCurses.cmake

@@ -29,6 +29,8 @@
 #
 # Set ``CURSES_NEED_NCURSES`` to ``TRUE`` before the
 # ``find_package(Curses)`` call if NCurses functionality is required.
+# Set ``CURSES_NEED_WIDE`` to ``TRUE`` before the
+# ``find_package(Curses)`` call if unicode functionality is required.
 #
 # Backward Compatibility
 # ^^^^^^^^^^^^^^^^^^^^^^
@@ -42,9 +44,20 @@
 
 include(${CMAKE_CURRENT_LIST_DIR}/CheckLibraryExists.cmake)
 
+# we don't know anything about cursesw, so only ncurses
+# may be ncursesw
+if(NOT CURSES_NEED_WIDE)
+  set(NCURSES_LIBRARY_NAME "ncurses")
+else()
+  set(NCURSES_LIBRARY_NAME "ncursesw")
+  # Also, if we are searchig fo wide curses - we are actually searching
+  # for ncurses, we don't know about any other unicode version.
+  set(CURSES_NEED_NCURSES TRUE)
+endif()
+
 find_library(CURSES_CURSES_LIBRARY NAMES curses )
 
-find_library(CURSES_NCURSES_LIBRARY NAMES ncurses )
+find_library(CURSES_NCURSES_LIBRARY NAMES "${NCURSES_LIBRARY_NAME}" )
 set(CURSES_USE_NCURSES FALSE)
 
 if(CURSES_NCURSES_LIBRARY  AND ((NOT CURSES_CURSES_LIBRARY) OR CURSES_NEED_NCURSES))
@@ -55,9 +68,15 @@ endif()
 # message.  Cygwin is an ncurses package, so force ncurses on
 # cygwin if the curses.h is missing
 if(CYGWIN)
+  if (CURSES_NEED_WIDE)
+    if(NOT EXISTS /usr/include/ncursesw/curses.h)
+      set(CURSES_USE_NCURSES TRUE)
+    endif()
+  else()
     if(NOT EXISTS /usr/include/curses.h)
       set(CURSES_USE_NCURSES TRUE)
     endif()
+  endif()
 endif()
 
 
@@ -96,17 +115,32 @@ if(CURSES_USE_NCURSES)
 
   # Use CURSES_NCURSES_INCLUDE_PATH if set, for compatibility.
   if(CURSES_NCURSES_INCLUDE_PATH)
+    if (CURSES_NEED_WIDE)
+      find_path(CURSES_INCLUDE_PATH
+        NAMES ncursesw/ncurses.h ncursesw/curses.h
+        PATHS ${CURSES_NCURSES_INCLUDE_PATH}
+        NO_DEFAULT_PATH
+        )
+    else()
       find_path(CURSES_INCLUDE_PATH
         NAMES ncurses/ncurses.h ncurses/curses.h ncurses.h curses.h
         PATHS ${CURSES_NCURSES_INCLUDE_PATH}
         NO_DEFAULT_PATH
         )
     endif()
+  endif()
 
+  if (CURSES_NEED_WIDE)
+    find_path(CURSES_INCLUDE_PATH
+      NAMES ncursesw/ncurses.h ncursesw/curses.h
+      HINTS "${_cursesParentDir}/include"
+      )
+  else()
     find_path(CURSES_INCLUDE_PATH
       NAMES ncurses/ncurses.h ncurses/curses.h ncurses.h curses.h
       HINTS "${_cursesParentDir}/include"
       )
+   endif()
 
   # Previous versions of FindCurses provided these values.
   if(NOT DEFINED CURSES_LIBRARY)
@@ -123,10 +157,14 @@ else()
   get_filename_component(_cursesLibDir "${CURSES_CURSES_LIBRARY}" PATH)
   get_filename_component(_cursesParentDir "${_cursesLibDir}" PATH)
 
+  #We can't find anything with CURSES_NEED_WIDE because we know
+  #only about ncursesw unicode curses version
+  if(NOT CURSES_NEED_WIDE)
     find_path(CURSES_INCLUDE_PATH
       NAMES curses.h
       HINTS "${_cursesParentDir}/include"
       )
+  endif()
 
   # Previous versions of FindCurses provided these values.
   if(NOT DEFINED CURSES_CURSES_H_PATH)
@@ -139,32 +177,45 @@ endif()
 
 # Report whether each possible header name exists in the include directory.
 if(NOT DEFINED CURSES_HAVE_NCURSES_NCURSES_H)
-  if(EXISTS "${CURSES_INCLUDE_PATH}/ncurses/ncurses.h")
+  if(CURSES_NEED_WIDE)
+    if(EXISTS "${CURSES_INCLUDE_PATH}/ncursesw/ncurses.h")
+      set(CURSES_HAVE_NCURSES_NCURSES_H "${CURSES_INCLUDE_PATH}/ncursesw/ncurses.h")
+    endif()
+  elseif(EXISTS "${CURSES_INCLUDE_PATH}/ncurses/ncurses.h")
     set(CURSES_HAVE_NCURSES_NCURSES_H "${CURSES_INCLUDE_PATH}/ncurses/ncurses.h")
-  else()
+  endif()
+  if(NOT DEFINED CURSES_HAVE_NCURSES_NCURSES_H)
     set(CURSES_HAVE_NCURSES_NCURSES_H "CURSES_HAVE_NCURSES_NCURSES_H-NOTFOUND")
   endif()
 endif()
 if(NOT DEFINED CURSES_HAVE_NCURSES_CURSES_H)
-  if(EXISTS "${CURSES_INCLUDE_PATH}/ncurses/curses.h")
+  if(CURSES_NEED_WIDE)
+    if(EXISTS "${CURSES_INCLUDE_PATH}/ncursesw/curses.h")
+      set(CURSES_HAVE_NCURSES_CURSES_H "${CURSES_INCLUDE_PATH}/ncursesw/curses.h")
+    endif()
+  elseif(EXISTS "${CURSES_INCLUDE_PATH}/ncurses/curses.h")
     set(CURSES_HAVE_NCURSES_CURSES_H "${CURSES_INCLUDE_PATH}/ncurses/curses.h")
-  else()
+  endif()
+  if(NOT DEFINED CURSES_HAVE_NCURSES_CURSES_H)
     set(CURSES_HAVE_NCURSES_CURSES_H "CURSES_HAVE_NCURSES_CURSES_H-NOTFOUND")
   endif()
 endif()
-if(NOT DEFINED CURSES_HAVE_NCURSES_H)
+if(NOT CURSES_NEED_WIDE)
+  #ncursesw can't be found for this paths
+  if(NOT DEFINED CURSES_HAVE_NCURSES_H)
     if(EXISTS "${CURSES_INCLUDE_PATH}/ncurses.h")
       set(CURSES_HAVE_NCURSES_H "${CURSES_INCLUDE_PATH}/ncurses.h")
     else()
       set(CURSES_HAVE_NCURSES_H "CURSES_HAVE_NCURSES_H-NOTFOUND")
     endif()
-endif()
+  endif()
-if(NOT DEFINED CURSES_HAVE_CURSES_H)
+  if(NOT DEFINED CURSES_HAVE_CURSES_H)
     if(EXISTS "${CURSES_INCLUDE_PATH}/curses.h")
       set(CURSES_HAVE_CURSES_H "${CURSES_INCLUDE_PATH}/curses.h")
     else()
       set(CURSES_HAVE_CURSES_H "CURSES_HAVE_CURSES_H-NOTFOUND")
     endif()
+  endif()
 endif()
 
 find_library(CURSES_FORM_LIBRARY form HINTS "${_cursesLibDir}")