fix: edge case when release had partial chapters

pnpm-lock.yaml

@@ -38,7 +38,7 @@ dependencies:
   electron-updater: 4.6.5
   jassub: 1.5.12
   js-levenshtein: 1.1.6
-  matroska-subtitles: github.com/ThaUnknown/matroska-subtitles/c227b6a679f9bf4243a5e65220e81b72c893a37a
+  matroska-subtitles: github.com/ThaUnknown/matroska-subtitles/6241556509536ff09ba2ea3f050ceb7a3f12190a
   mime: 3.0.0
   p2pcf: github.com/ThaUnknown/p2pcf/faefe2854c817315530636a58d07726de7050561
   perfect-seekbar: 1.1.0
@@ -3254,8 +3254,8 @@ packages:
     version: 2.0.5
     dev: false
 
-  github.com/ThaUnknown/matroska-subtitles/c227b6a679f9bf4243a5e65220e81b72c893a37a:
-    resolution: {tarball: https://codeload.github.com/ThaUnknown/matroska-subtitles/tar.gz/c227b6a679f9bf4243a5e65220e81b72c893a37a}
+  github.com/ThaUnknown/matroska-subtitles/6241556509536ff09ba2ea3f050ceb7a3f12190a:
+    resolution: {tarball: https://codeload.github.com/ThaUnknown/matroska-subtitles/tar.gz/6241556509536ff09ba2ea3f050ceb7a3f12190a}
     name: matroska-subtitles
     version: 3.3.2
     dependencies:

src/renderer/src/lib/Player/Player.svelte

@@ -677,6 +677,30 @@
       if (time < (chapter.end / 1000) && time >= (chapter.start / 1000)) return chapter
     }
   }
+
+  // remaps chapters to what perfect-seekbar uses and adds potentially missing chapters
+  function sanitiseChapters (chapters, safeduration) {
+    const sanitised = []
+    let sum = 0
+    for (const { start, end, text } of chapters) {
+      if (!sanitised.length && start !== 0) {
+        const size = start / 10 / safeduration
+        sum += size
+        sanitised.push({ size })
+      }
+      const size = (end / 10 / safeduration) - (start / 10 / safeduration)
+      sum += size
+      sanitised.push({
+        size,
+        text
+      })
+    }
+    if (sum !== 100) {
+      sanitised.push({ size: 100 - sum })
+    }
+    return sanitised
+  }
+
   const thumbCanvas = document.createElement('canvas')
   thumbCanvas.width = 200
   const thumbnailData = {
@@ -943,10 +967,7 @@
         bind:progress={progress}
         on:seeking={handleMouseDown}
         on:seeked={handleMouseUp}
-        chapters={chapters.map(({ start, end, text }) => ({
-          size: (end / 10 / safeduration) - (start / 10 / safeduration),
-          text
-        }))}
+        chapters={sanitiseChapters(chapters, safeduration)}
         {getThumbnail}
       />
     </div>