patch 8.0.1711: term_setsize() is not implemented yet

Problem:    Term_setsize() is not implemented yet.
Solution:   Implement it.
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 4b09951..599d61a 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -876,6 +876,7 @@
 # endif
     {"term_setkill",	2, 2, f_term_setkill},
     {"term_setrestore",	2, 2, f_term_setrestore},
+    {"term_setsize",	3, 3, f_term_setsize},
     {"term_start",	1, 2, f_term_start},
     {"term_wait",	1, 2, f_term_wait},
 #endif
diff --git a/src/proto/terminal.pro b/src/proto/terminal.pro
index f7cea5a..78b640f 100644
--- a/src/proto/terminal.pro
+++ b/src/proto/terminal.pro
@@ -32,19 +32,20 @@
 void f_term_dumpdiff(typval_T *argvars, typval_T *rettv);
 void f_term_dumpload(typval_T *argvars, typval_T *rettv);
 void f_term_getaltscreen(typval_T *argvars, typval_T *rettv);
-void f_term_getansicolors(typval_T *argvars, typval_T *rettv);
 void f_term_getattr(typval_T *argvars, typval_T *rettv);
 void f_term_getcursor(typval_T *argvars, typval_T *rettv);
 void f_term_getjob(typval_T *argvars, typval_T *rettv);
 void f_term_getline(typval_T *argvars, typval_T *rettv);
 void f_term_getscrolled(typval_T *argvars, typval_T *rettv);
 void f_term_getsize(typval_T *argvars, typval_T *rettv);
+void f_term_setsize(typval_T *argvars, typval_T *rettv);
 void f_term_getstatus(typval_T *argvars, typval_T *rettv);
 void f_term_gettitle(typval_T *argvars, typval_T *rettv);
 void f_term_gettty(typval_T *argvars, typval_T *rettv);
 void f_term_list(typval_T *argvars, typval_T *rettv);
 void f_term_scrape(typval_T *argvars, typval_T *rettv);
 void f_term_sendkeys(typval_T *argvars, typval_T *rettv);
+void f_term_getansicolors(typval_T *argvars, typval_T *rettv);
 void f_term_setansicolors(typval_T *argvars, typval_T *rettv);
 void f_term_setrestore(typval_T *argvars, typval_T *rettv);
 void f_term_setkill(typval_T *argvars, typval_T *rettv);
diff --git a/src/terminal.c b/src/terminal.c
index f980a09..09d4887 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -40,7 +40,6 @@
  * TODO:
  * - Win32: Make terminal used for :!cmd in the GUI work better.  Allow for
  *   redirection.  Probably in call to channel_set_pipes().
- * - implement term_setsize()
  * - add an optional limit for the scrollback size.  When reaching it remove
  *   10% at the start.
  * - Copy text in the vterm to the Vim buffer once in a while, so that
@@ -4603,6 +4602,31 @@
 }
 
 /*
+ * "term_setsize(buf, rows, cols)" function
+ */
+    void
+f_term_setsize(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
+{
+    buf_T	*buf = term_get_buf(argvars, "term_setsize()");
+    term_T	*term;
+    varnumber_T rows, cols;
+
+    if (buf == NULL || buf->b_term->tl_vterm == NULL)
+	return;
+    term = buf->b_term;
+    rows = get_tv_number(&argvars[1]);
+    rows = rows <= 0 ? term->tl_rows : rows;
+    cols = get_tv_number(&argvars[2]);
+    cols = cols <= 0 ? term->tl_cols : cols;
+    vterm_set_size(term->tl_vterm, rows, cols);
+    /* handle_resize() will resize the windows */
+
+    /* Get and remember the size we ended up with.  Update the pty. */
+    vterm_get_size(term->tl_vterm, &term->tl_rows, &term->tl_cols);
+    term_report_winsize(term, term->tl_rows, term->tl_cols);
+}
+
+/*
  * "term_getstatus(buf)" function
  */
     void
@@ -5432,7 +5456,7 @@
 }
 
 /*
- * Request size to terminal.
+ * Report the size to the terminal.
  */
     static void
 term_report_winsize(term_T *term, int rows, int cols)
@@ -5514,7 +5538,7 @@
 }
 
 /*
- * Request size to terminal.
+ * Report the size to the terminal.
  */
     static void
 term_report_winsize(term_T *term, int rows, int cols)
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index e97ee06..137de7d 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -286,9 +286,18 @@
 
   vsplit
   exe 'terminal ++rows=5 ++cols=33 ' . cmd
-  let size = term_getsize('')
+  call assert_equal([5, 33], term_getsize(''))
+
+  call term_setsize('', 6, 0)
+  call assert_equal([6, 33], term_getsize(''))
+
+  call term_setsize('', 0, 35)
+  call assert_equal([6, 35], term_getsize(''))
+
+  call term_setsize('', 7, 30)
+  call assert_equal([7, 30], term_getsize(''))
+
   bwipe!
-  call assert_equal([5, 33], size)
 
   call term_start(cmd, {'term_rows': 6, 'term_cols': 36})
   let size = term_getsize('')
diff --git a/src/version.c b/src/version.c
index b340f11..255e24b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -763,6 +763,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1711,
+/**/
     1710,
 /**/
     1709,