From: NeilBrown <neil@brown.name>
Date: Tue, 8 Aug 2023 22:44:02 +0000 (+1000)
Subject: render-lines: call_render_line_to_point never returns error
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=355425350289d9af62bb55f230417614108c9ce9;p=edlib.git

render-lines: call_render_line_to_point never returns error

Don't test for call_render_line_to_point returning < 0, as it doesn't.
Don't even test for == 0.  That is a valid answer and we no longer call
call_render_line_to_point() in a situation where that causes problems.

Signed-off-by: NeilBrown <neil@brown.name>
---

diff --git a/DOC/TODO.md b/DOC/TODO.md
index 346ab4bd..0eb4a15d 100644
--- a/DOC/TODO.md
+++ b/DOC/TODO.md
@@ -16,7 +16,7 @@ the file.
 - [ ] should pane ->cx,cy be a struct xy??
 - [X] revalidate_start shouldn't find cursor on line where it is known
       not to be
-- [ ] call_render_line_to_point() never returns negative - why do we check?
+- [X] call_render_line_to_point() never returns negative - why do we check?
 - [ ] should pane_resize() report if any change happened?
 - [ ] I think I want a "Workspaces" concept, maybe tabbed set of tile
       collections.  I would have one of mail and one for each project
diff --git a/render-lines.c b/render-lines.c
index 1f65d00f..50dcbc22 100644
--- a/render-lines.c
+++ b/render-lines.c
@@ -1137,17 +1137,15 @@ static int revalidate_start(struct rl_data *rl safe,
 			 */
 			int offset = call_render_line_to_point(focus,
 							       pm, m);
-			if (offset >= 0) {
-				measure_line(p, focus, m, offset);
-				if (hp->cy >= rl->skip_height + rl->margin)
-					/* Cursor is visible on this line
-					 * and after margin from top.
-					 */
-					on_screen = True;
-				else if (start_of_file && rl->skip_height == 0)
-					/* Cannot make more margin space */
-					on_screen = True;
-			}
+			measure_line(p, focus, m, offset);
+			if (hp->cy >= rl->skip_height + rl->margin)
+				/* Cursor is visible on this line
+				 * and after margin from top.
+				 */
+				on_screen = True;
+			else if (start_of_file && rl->skip_height == 0)
+				/* Cannot make more margin space */
+				on_screen = True;
 		} else if (pm && m2 && y >= p->h && m->seq < pm->seq &&
 			   mark_ordered_not_same(pm, m2)) {
 			/* point might be in this line, but off end
@@ -1155,17 +1153,16 @@ static int revalidate_start(struct rl_data *rl safe,
 			 */
 			int offset = call_render_line_to_point(focus,
 							       pm, m);
-			if (offset > 0) {
-				int lh;
-				measure_line(p, focus, m, offset);
-				lh = attr_find_int(hp->attrs,
-						   "line-height");
-				if (lh <= 0)
-					lh = 1;
-				if (y - hp->h + hp->cy <= p->h - lh - rl->margin) {
-					/* Cursor is on screen */
-					on_screen = True;
-				}
+			int lh;
+			measure_line(p, focus, m, offset);
+			lh = attr_find_int(hp->attrs,
+					   "line-height");
+			if (lh <= 0)
+				lh = 1;
+			if (hp->cy >= 0 &&
+			    y - hp->h + hp->cy <= p->h - lh - rl->margin) {
+				/* Cursor is on screen */
+				on_screen = True;
 			}
 		} else if (pm && mark_ordered_or_same(m, pm) && m2 &&
 			   (mark_ordered_not_same(pm, m2) ||
@@ -1179,18 +1176,16 @@ static int revalidate_start(struct rl_data *rl safe,
 			else {
 				int offset = call_render_line_to_point(
 					focus, pm, m);
-				if (offset > 0) {
-					int lh;
-					int cy;
-					measure_line(p, focus, m, offset);
-					lh = attr_find_int(hp->attrs,
-							   "line-height");
-					cy = y - hp->h + hp->cy;
-					if (cy >= rl->margin &&
-					    cy <= p->h - rl->margin - lh)
-						/* Cursor at least margin from edge */
-						on_screen = True;
-				}
+				int lh;
+				int cy;
+				measure_line(p, focus, m, offset);
+				lh = attr_find_int(hp->attrs,
+						   "line-height");
+				cy = y - hp->h + hp->cy;
+				if (cy >= rl->margin &&
+				    cy <= p->h - rl->margin - lh)
+					/* Cursor at least margin from edge */
+					on_screen = True;
 			}
 		}
 	}
@@ -1625,8 +1620,6 @@ DEF_CMD(render_lines_action)
 	if (!v || !v->mdata || !mark_ordered_or_same(v, m))
 		return Efallthrough;
 	offset = call_render_line_to_point(focus, m, v);
-	if (offset < 0)
-		return Efallthrough;
 	measure_line(p, focus, v, offset, &attr);
 	if (!attr)
 		return Efallthrough;