Fix hscrolling with line numbers on TTY frames

* src/xdisp.c (hscroll_window_tree): Correct the X offset
calculations on TTY frames.
* src/term.c (produce_glyphs): Use it->lnum_pixel_width instead of
a kludge using it->lnum_width.

src/term.c

@@ -1584,14 +1584,16 @@ produce_glyphs (struct it *it)
     {
       int absolute_x = (it->current_x
 			+ it->continuation_lines_width);
-      /* Adjust for line numbers.  Kludge alert: the "2" below is
-	 because we add 2 blanks to the actual line number.  */
+      int x0 = absolute_x;
+      /* Adjust for line numbers.  */
       if (!NILP (Vdisplay_line_numbers))
-	absolute_x -= it->lnum_width + 2 - it->w->hscroll;
+	absolute_x -= it->lnum_pixel_width;
       int next_tab_x
 	= (((1 + absolute_x + it->tab_width - 1)
 	    / it->tab_width)
 	   * it->tab_width);
+      if (!NILP (Vdisplay_line_numbers))
+	next_tab_x += it->lnum_pixel_width;
       int nspaces;
 
       /* If part of the TAB has been displayed on the previous line
@@ -1599,7 +1601,7 @@ produce_glyphs (struct it *it)
 	 been incremented already by the part that fitted on the
 	 continued line.  So, we will get the right number of spaces
 	 here.  */
-      nspaces = next_tab_x - absolute_x;
+      nspaces = next_tab_x - x0;
 
       if (it->glyph_row)
 	{

src/xdisp.c

@@ -13100,6 +13100,12 @@ hscroll_window_tree (Lisp_Object window)
 		    }
 		}
 	    }
+	  if (cursor_row->truncated_on_left_p)
+	    {
+	      /* On TTY frames, don't count the left truncation glyph.  */
+	      struct frame *f = XFRAME (WINDOW_FRAME (w));
+	      x_offset -= (FRAME_TERMCAP_P (f) || FRAME_MSDOS_P (f));
+	    }
 
 	  text_area_width = window_box_width (w, TEXT_AREA);
 
@@ -28004,7 +28010,8 @@ x_produce_glyphs (struct it *it)
 		x -= it->lnum_pixel_width;
 	      int next_tab_x = ((1 + x + tab_width - 1) / tab_width) * tab_width;
 	      if (!NILP (Vdisplay_line_numbers))
-		next_tab_x += it->lnum_pixel_width;
+		next_tab_x += (it->lnum_pixel_width
+			       - it->w->hscroll * font->space_width);
 
 	      /* If the distance from the current position to the next tab
 		 stop is less than a space character width, use the