patch 8.1.1972: no proper test for getchar()

Problem:    No proper test for getchar().
Solution:   Add a test with special characters.
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 20718bc..d5ce5f0 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1314,6 +1314,23 @@
   unlet g:typed2
 endfunc
 
+func Test_getchar()
+  call feedkeys('a', '')
+  call assert_equal(char2nr('a'), getchar())
+
+  call test_setmouse(1, 3)
+  let v:mouse_win = 9
+  let v:mouse_winid = 9
+  let v:mouse_lnum = 9
+  let v:mouse_col = 9
+  call feedkeys("\<S-LeftMouse>", '')
+  call assert_equal("\<S-LeftMouse>", getchar())
+  call assert_equal(1, v:mouse_win)
+  call assert_equal(win_getid(1), v:mouse_winid)
+  call assert_equal(1, v:mouse_lnum)
+  call assert_equal(3, v:mouse_col)
+endfunc
+
 func Test_libcall_libcallnr()
   if !has('libcall')
     return
diff --git a/src/version.c b/src/version.c
index 85526b6..321da51 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1972,
+/**/
     1971,
 /**/
     1970,