From: Simon Tatham <anakin@pobox.com>
Date: Sat, 6 Jan 2024 11:57:40 +0000 (+0000)
Subject: Fix clipping of initial file positions.
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=f972070d04bcbb5c62116dafa59dcc72ea131911;p=mastodonochrome.git

Fix clipping of initial file positions.

It's not enough to just modify the item index - we also have to reset
the line number.
---

diff --git a/src/file.rs b/src/file.rs
index 408eb93..2df8251 100644
--- a/src/file.rs
+++ b/src/file.rs
@@ -38,6 +38,21 @@ impl FilePosition {
     fn item_bottom(item: isize) -> Self {
         FilePosition { item, line: 1, width: None }
     }
+
+    fn clip(self, first_index: isize, last_index: isize) -> Self {
+        let pos = self;
+        let pos = if pos.item < first_index {
+            Self::item_top(first_index)
+        } else {
+            pos
+        };
+        let pos = if pos.item > last_index {
+            Self::item_bottom(last_index)
+        } else {
+            pos
+        };
+        pos
+    }
 }
 
 trait FileDataSource {
@@ -325,8 +340,8 @@ impl<Type: FileType, Source: FileDataSource> File<Type, Source> {
         let mut initial_pos = initial_pos.unwrap_or_else(
             || FilePosition::item_bottom(isize::MAX));
 
-        initial_pos.item = max(initial_pos.item, contents.first_index());
-        initial_pos.item = min(initial_pos.item, contents.last_index());
+        initial_pos = initial_pos.clip(
+            contents.first_index(), contents.last_index());
 
         let ff = File {
             contents,