tweaks: rename need_horizontal_scroll() to line_needs_update()

The old name made it sound as if it didn't apply in softwrap mode.  But
it does: in softwrap mode a line needs updating  when the mark is on.

src/move.c

@@ -369,7 +369,7 @@ void do_home(void)
 
     openfile->placewewant = xplustabs();
 
-    if (need_horizontal_scroll(was_column, openfile->placewewant))
+    if (line_needs_update(was_column, openfile->placewewant))
 	update_line(openfile->current, openfile->current_x);
 }
 
@@ -381,7 +381,7 @@ void do_end(void)
     openfile->current_x = strlen(openfile->current->data);
     openfile->placewewant = xplustabs();
 
-    if (need_horizontal_scroll(was_column, openfile->placewewant))
+    if (line_needs_update(was_column, openfile->placewewant))
 	update_line(openfile->current, openfile->current_x);
 
     ensure_line_is_visible();
@@ -414,10 +414,10 @@ void do_up(bool scroll_only)
     /* If the lines weren't already redrawn, see if they need to be. */
     if (openfile->current_y > 0) {
 	/* Redraw the prior line if it was horizontally scrolled. */
-	if (need_horizontal_scroll(was_column, 0))
+	if (line_needs_update(was_column, 0))
 	    update_line(openfile->current->next, 0);
 	/* Redraw the current line if it needs to be horizontally scrolled. */
-	if (need_horizontal_scroll(0, xplustabs()))
+	if (line_needs_update(0, xplustabs()))
 	    update_line(openfile->current, openfile->current_x);
     }
 }
@@ -492,10 +492,10 @@ void do_down(bool scroll_only)
     /* If the lines weren't already redrawn, see if they need to be. */
     if (openfile->current_y < editwinrows - 1) {
 	/* Redraw the prior line if it was horizontally scrolled. */
-	if (need_horizontal_scroll(was_column, 0))
+	if (line_needs_update(was_column, 0))
 	    update_line(openfile->current->prev, 0);
 	/* Redraw the current line if it needs to be horizontally scrolled. */
-	if (need_horizontal_scroll(0, xplustabs()))
+	if (line_needs_update(0, xplustabs()))
 	    update_line(openfile->current, openfile->current_x);
     }
 }
@@ -535,7 +535,7 @@ void do_left(void)
 
     openfile->placewewant = xplustabs();
 
-    if (need_horizontal_scroll(was_column, openfile->placewewant))
+    if (line_needs_update(was_column, openfile->placewewant))
 	update_line(openfile->current, openfile->current_x);
 }
 
@@ -557,7 +557,7 @@ void do_right(void)
 
     openfile->placewewant = xplustabs();
 
-    if (need_horizontal_scroll(was_column, openfile->placewewant))
+    if (line_needs_update(was_column, openfile->placewewant))
 	update_line(openfile->current, openfile->current_x);
 
     if (openfile->current_x == 0)

src/proto.h

@@ -706,7 +706,7 @@ void reset_cursor(void);
 void edit_draw(filestruct *fileptr, const char *converted,
 	int line, size_t from_col);
 int update_line(filestruct *fileptr, size_t index);
-bool need_horizontal_scroll(const size_t old_column, const size_t new_column);
+bool line_needs_update(const size_t old_column, const size_t new_column);
 int go_back_chunks(int nrows, filestruct **line, size_t *leftedge);
 int go_forward_chunks(int nrows, filestruct **line, size_t *leftedge);
 bool less_than_a_screenful(size_t was_lineno, size_t was_leftedge);

src/winio.c

@@ -2715,9 +2715,10 @@ int update_line(filestruct *fileptr, size_t index)
     return 1;
 }
 
-/* Check whether old_column and new_column are on different "pages" (or that
- * the mark is on), which means that the relevant line needs to be redrawn. */
-bool need_horizontal_scroll(const size_t old_column, const size_t new_column)
+/* Check whether the mark is on, or whether old_column and new_column are on
+ * different "pages" (in softwrap mode, only the former applies), which means
+ * that the relevant line needs to be redrawn. */
+bool line_needs_update(const size_t old_column, const size_t new_column)
 {
 #ifndef NANO_TINY
     if (openfile->mark_set)
@@ -2934,7 +2935,7 @@ void edit_scroll(scroll_dir direction, int nrows)
     for (i = nrows; i > 0 && line != NULL; i--) {
 	if ((i == nrows && direction == DOWNWARD) ||
 			(i == 1 && direction == UPWARD)) {
-	    if (need_horizontal_scroll(openfile->placewewant, 0))
+	    if (line_needs_update(openfile->placewewant, 0))
 		update_line(line, (line == openfile->current) ?
 			openfile->current_x : 0);
 	} else
@@ -3016,7 +3017,7 @@ void edit_redraw(filestruct *old_current)
 
     /* Update current if the mark is on or it has changed "page", or if it
      * differs from old_current and needs to be horizontally scrolled. */
-    if (need_horizontal_scroll(was_pww, openfile->placewewant) ||
+    if (line_needs_update(was_pww, openfile->placewewant) ||
 			(old_current != openfile->current &&
 			get_page_start(openfile->placewewant) > 0))
 	update_line(openfile->current, openfile->current_x);