only append 'generic' TCL include path to 'TCL_INCLUDES' if it exists

Squashes numerous -Wmissing-include-dirs compilation warnings.

diff --git a/configure.ac b/configure.ac
index 450b03577351be2ffe34b1c60032c81349e2b302..64002620a6ea04b6c66005c155355c9b47063c6b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1384,6 +1384,9 @@ if test "x$use_tcl" = "x"; then
 
   if test -f ${TCLSH_EXEC_PREFIX}/include/tcl${TCL_VERSION_FOUND}/tcl.h; then
     TCL_INCLUDES="-I${TCLSH_EXEC_PREFIX}/include/tcl${TCL_VERSION_FOUND} -I${TCLSH_EXEC_PREFIX}/include/tcl${TCL_VERSION_FOUND}/generic"
+    if test -d ${TCLSH_EXEC_PREFIX}/include/tcl${TCL_VERSION_FOUND}/generic; then
+      TCL_INCLUDES="${TCL_INCLUDES} -I${TCLSH_EXEC_PREFIX}/include/tcl${TCL_VERSION_FOUND}/generic"
+    fi
   else
     if test "x${TCLSH_EXEC_PREFIX}" != "x/usr" -a -f ${TCLSH_EXEC_PREFIX}/include/tcl.h; then
       TCL_INCLUDES=-I${TCLSH_EXEC_PREFIX}/include