patch 8.1.1916: trying to allocate negative amount of memory closing popup

Problem:    Trying to allocate negative amount of memory when closing a popup.
Solution:   Check the rows are not out of bounds.  Don't finish a selection if
            it was never started.
diff --git a/src/ui.c b/src/ui.c
index 61f19bc..7095eda 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -1184,7 +1184,10 @@
 
     if (button == MOUSE_RELEASE)
     {
-	/* Check to make sure we have something selected */
+	if (cb->state != SELECT_IN_PROGRESS)
+	    return;
+
+	// Check to make sure we have something selected
 	if (cb->start.lnum == cb->end.lnum && cb->start.col == cb->end.col)
 	{
 #ifdef FEAT_GUI
@@ -1591,6 +1594,8 @@
 	col1 = clip_star.min_col;
     if (col2 > clip_star.max_col)
 	col2 = clip_star.max_col;
+    if (row1 > clip_star.max_row || row2 < clip_star.min_row)
+	return;
     if (row1 < clip_star.min_row)
 	row1 = clip_star.min_row;
     if (row2 > clip_star.max_row)
diff --git a/src/version.c b/src/version.c
index 8ece6f1..51851e3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1916,
+/**/
     1915,
 /**/
     1914,