From: Sergei Golovan <sgolovan@nes.ru>
Date: Sun, 18 Mar 2018 21:00:53 +0300
Subject: Enable Itcl 4 for the build

This includes switching ON variable USE_INCRTCL_VERSION_4 and adding
the itcl suffix to the include search paths because for tcl-itcl4 the
headers are placed in /usr/include/itcl.
---
 cmake/modules/tcl-related.cmake | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/cmake/modules/tcl-related.cmake b/cmake/modules/tcl-related.cmake
index 68587cb..e1fcb32 100644
--- a/cmake/modules/tcl-related.cmake
+++ b/cmake/modules/tcl-related.cmake
@@ -32,7 +32,7 @@ else(DEFAULT_NO_BINDINGS)
   option(ENABLE_itk "Enable Itk interface code" ON)
 endif(DEFAULT_NO_BINDINGS)
 
-option(USE_INCRTCL_VERSION_4 "Use version 4 of Itcl and Itcl, version 4.1 of Iwidgets" OFF)
+option(USE_INCRTCL_VERSION_4 "Use version 4 of Itcl and Itcl, version 4.1 of Iwidgets" ON)
 
 option(USE_TCL_TK_STUBS "Use Tcl/Tk stubs libraries" OFF)
 
@@ -183,7 +183,7 @@ if(ENABLE_tcl)
       message(STATUS "PLPLOT_ITCL_VERSION = ${PLPLOT_ITCL_VERSION}")
       string(SUBSTRING ${PLPLOT_ITCL_VERSION} 0 1 SHORT_PLPLOT_ITCL_VERSION)
       # N.B. Debian jessie itcl3-dev package stores itcl.h in /usr/include/itcl${SHORT_PLPLOT_ITCL_VERSION}
-      find_path(ITCL_INCLUDE_PATH itcl.h HINTS "${TCL_INCLUDE_PATH}" PATH_SUFFIXES itcl${SHORT_PLPLOT_ITCL_VERSION})
+      find_path(ITCL_INCLUDE_PATH itcl.h HINTS "${TCL_INCLUDE_PATH}" PATH_SUFFIXES itcl itcl${SHORT_PLPLOT_ITCL_VERSION})
 
       if(ITCL_INCLUDE_PATH)
         message(STATUS "Looking for itcl.h - found")
@@ -416,7 +416,7 @@ void main(void){}
       endif(NOT USE_INCRTCL_VERSION_4)
       message(STATUS "PLPLOT_ITK_VERSION = ${PLPLOT_ITK_VERSION}")
       # N.B. Debian jessie itk3-dev package stores itk.h in /usr/include/itcl${SHORT_PLPLOT_ITCL_VERSION}
-      find_path(ITK_INCLUDE_PATH itk.h HINTS "${TCL_INCLUDE_PATH}" PATH_SUFFIXES itcl${SHORT_PLPLOT_ITCL_VERSION})
+      find_path(ITK_INCLUDE_PATH itk.h HINTS "${TCL_INCLUDE_PATH}" PATH_SUFFIXES itcl itcl${SHORT_PLPLOT_ITCL_VERSION})
 
       if(ITK_INCLUDE_PATH)
         message(STATUS "Looking for itk.h - found")
