patch 8.2.1239: "maxwidth" in 'completepopup' not obeyed

Problem:    "maxwidth" in 'completepopup' not obeyed. (Jay Sitter)
Solution:   Add separate field for value from option. (closes #6470)

src/popupmenu.c

@@ -642,6 +642,7 @@ pum_position_info_popup(win_T *wp)
     int col = pum_col + pum_width + pum_scrollbar + 1;
     int row = pum_row;
     int botpos = POPPOS_BOTLEFT;
+    int	used_maxwidth_opt = FALSE;
 
     wp->w_popup_pos = POPPOS_TOPLEFT;
     if (Columns - col < 20 && Columns - col < pum_col)
@@ -654,6 +655,12 @@ pum_position_info_popup(win_T *wp)
     else
 	wp->w_maxwidth = Columns - col + 1;
     wp->w_maxwidth -= popup_extra_width(wp);
+    if (wp->w_maxwidth_opt > 0 && wp->w_maxwidth > wp->w_maxwidth_opt)
+    {
+	// option value overrules computed value
+	wp->w_maxwidth = wp->w_maxwidth_opt;
+	used_maxwidth_opt = TRUE;
+    }
 
     row -= popup_top_extra(wp);
     if (wp->w_popup_flags & POPF_INFO_MENU)
@@ -673,7 +680,7 @@ pum_position_info_popup(win_T *wp)
 	row += pum_selected - pum_first + 1;
 
     wp->w_popup_flags &= ~POPF_HIDDEN;
-    if (wp->w_maxwidth < 10)
+    if (wp->w_maxwidth < 10 && !used_maxwidth_opt)
 	// The popup is not going to fit or will overlap with the cursor
 	// position, hide the popup.
 	wp->w_popup_flags |= POPF_HIDDEN;

src/popupwin.c

@@ -1620,6 +1620,7 @@ parse_popup_option(win_T *wp, int is_preview)
 		if (is_preview)
 		    wp->w_minwidth = x;
 		wp->w_maxwidth = x;
+		wp->w_maxwidth_opt = x;
 	    }
 	}
 	else if (STRNCMP(s, "highlight:", 10) == 0)

src/structs.h

@@ -3302,6 +3302,7 @@ struct window_S
     int		w_minwidth;	    // "minwidth" for popup window
     int		w_maxheight;	    // "maxheight" for popup window
     int		w_maxwidth;	    // "maxwidth" for popup window
+    int		w_maxwidth_opt;	    // maxwidth from option
     int		w_wantline;	    // "line" for popup window
     int		w_wantcol;	    // "col" for popup window
     int		w_firstline;	    // "firstline" for popup window

src/testdir/dumps/Test_popupwin_infopopup_9.dump

@@ -0,0 +1,14 @@
+|a+0&#ffffff0|w|o|r|d| @69
+|t|e|s|a|w|o|r|d> @66
+|~+0#4040ff13&| | +0#0000001#e0e0e08|w|r|d| @4|W| |e|x|t|r|a| |t|e|x|t| @1| +0#0000000#0000001| +0#0000001#e0e0e08|w|o|r|d|s| |a|r|e| @1| +0#4040ff13#ffffff0@36
+|~| | +0#0000001#ffd7ff255|a|n|o|t|w|r|d| |W| |e|x|t|r|a| |t|e|x|t| @1| +0#0000000#0000001| +0#0000001#e0e0e08|c|o@1|l| @6| +0#4040ff13#ffffff0@36
+|~| | +0#0000001#ffd7ff255|n|o|a|w|r|d| @1|W| |e|x|t|r|a| |t|e|x|t| @1| +0#0000000#a8a8a8255| +0#4040ff13#ffffff0@48
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |U|s|e|r| |d|e|f|i|n|e|d| |c|o|m|p|l|e|t|i|o|n| |(|^|U|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |1| |o|f| |4| +0#0000000&@26

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1239,
 /**/
     1238,
 /**/