Merge lines.love

commands.lua

@@ -813,7 +813,7 @@ function populate_errors_column(column)
   pane.line_height = Line_height
   pane.em = Em
   pane.editable = false
-  edit.fixup_cursor(pane)
+  edit.check_locs(pane)
   pane.title = '(do not edit)'
   Text.redraw_all(pane)
   table.insert(column, pane)

edit.lua

@@ -112,10 +112,32 @@ function edit.initialize_state(top, left, right, font_height, line_height)  -- c
   return result
 end  -- App.initialize_state
 
-function edit.fixup_cursor(State)
+function edit.check_locs(State)
+  -- if State is inconsistent (i.e. file changed by some other program),
+  --   throw away all cursor state entirely
+  if edit.invalid1(State, State.screen_top1)
+      or edit.invalid1(State, State.cursor1)
+      or not edit.cursor_on_text(State)
+      or not Text.le1(State.screen_top1, State.cursor1) then
+    State.screen_top1 = {line=1, pos=1}
+    edit.put_cursor_on_first_text_line(State)
+  end
+end
+
+function edit.invalid1(State, loc1)
+  return loc1.line > #State.lines
+      or loc1.pos > #State.lines[loc1.line].data
+end
+
+function edit.cursor_on_text(State)
+  return State.cursor1.line <= #State.lines
+      and State.lines[State.cursor1.line].mode == 'text'
+end
+
+function edit.put_cursor_on_first_text_line(State)
   for i,line in ipairs(State.lines) do
     if line.mode == 'text' then
-      State.cursor1.line = i
+      State.cursor1 = {line=i, pos=1}
       break
     end
   end

run.lua

@@ -235,7 +235,7 @@ function load_pane(id)
   result.line_height = Line_height
   result.em = Em
   result.editable = false
-  edit.fixup_cursor(result)
+  edit.check_locs(result)
   Text.redraw_all(result)
   return result
 end
@@ -883,7 +883,7 @@ function search_next()
   for current_pane_index=Cursor_pane.row+1,#Surface[Cursor_pane.col] do
     local pane = Surface[Cursor_pane.col][current_pane_index]
     pane.cursor1 = {line=1, pos=1}
-    edit.fixup_cursor(pane)
+    edit.check_locs(pane)
     pane.screen_top1 = {line=1, pos=1}
     if search_next_in_pane(pane) then
       Cursor_pane.row = current_pane_index
@@ -896,7 +896,7 @@ function search_next()
   while true do
     for current_pane_index,pane in ipairs(Surface[current_column_index]) do
       pane.cursor1 = {line=1, pos=1}
-      edit.fixup_cursor(pane)
+      edit.check_locs(pane)
       pane.screen_top1 = {line=1, pos=1}
       if search_next_in_pane(pane) then
         Cursor_pane = {col=current_column_index, row=current_pane_index}
@@ -924,7 +924,7 @@ function search_next()
   local pane = Surface[Cursor_pane.col][Cursor_pane.row]
   local old_cursor = pane.cursor1
   pane.cursor1 = {line=1, pos=1}
-  edit.fixup_cursor(pane)
+  edit.check_locs(pane)
   pane.screen_top1 = {line=1, pos=1}
   if search_next_in_pane(pane) then
     if Text.lt1(pane.cursor1, old_cursor) then

source.lua

@@ -88,6 +88,7 @@ function source.initialize_edit_side()
     Editor_state.screen_top1 = {line=1, pos=1}
     Editor_state.cursor1 = {line=1, pos=1}
   end
+  edit.check_locs(Editor_state)
 
   -- We currently start out with side B collapsed.
   -- Other options:

source_edit.lua

@@ -115,10 +115,32 @@ function edit.initialize_state(top, left, right, font_height, line_height)  -- c
   return result
 end  -- App.initialize_state
 
-function edit.fixup_cursor(State)
+function edit.check_locs(State)
+  -- if State is inconsistent (i.e. file changed by some other program),
+  --   throw away all cursor state entirely
+  if edit.invalid1(State, State.screen_top1)
+      or edit.invalid1(State, State.cursor1)
+      or not edit.cursor_on_text(State)
+      or not Text.le1(State.screen_top1, State.cursor1) then
+    State.screen_top1 = {line=1, pos=1}
+    edit.put_cursor_on_first_text_line(State)
+  end
+end
+
+function edit.invalid1(State, loc1)
+  return loc1.line > #State.lines
+      or loc1.pos > #State.lines[loc1.line].data
+end
+
+function edit.cursor_on_text(State)
+  return State.cursor1.line <= #State.lines
+      and State.lines[State.cursor1.line].mode == 'text'
+end
+
+function edit.put_cursor_on_first_text_line(State)
   for i,line in ipairs(State.lines) do
     if line.mode == 'text' then
-      State.cursor1.line = i
+      State.cursor1 = {line=i, pos=1}
       break
     end
   end