Fix next chapter button occasionally jumping to the last page of the current chapter (mihonapp/mihon#1920)

(cherry picked from commit 941dde341eb11703eadae543f351c9284617541c)

CHANGELOG.md

@@ -16,6 +16,7 @@ The format is a modified version of [Keep a Changelog](https://keepachangelog.co
 
 ### Fixes
 - Fix Bangumi search results including novels ([@MajorTanya](https://github.com/MajorTanya)) ([#1885](https://github.com/mihonapp/mihon/pull/1885))
+- Fix next chapter button occasionally jumping to the last page of the current chapter ([@perokhe](https://github.com/perokhe)) ([#1920](https://github.com/mihonapp/mihon/pull/1920))
 
 ## [v0.18.0] - 2025-03-20
 ### Added

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewer.kt

@@ -116,11 +116,7 @@ abstract class PagerViewer(
         pager.offscreenPageLimit = 1
         pager.id = R.id.reader_pager
         pager.adapter = adapter
-        pager.addOnPageChangeListener(
-            // SY -->
-            pagerListener,
-            // SY <--
-        )
+        pager.addOnPageChangeListener(pagerListener)
         pager.tapListener = { event ->
             val viewPosition = IntArray(2)
             pager.getLocationOnScreen(viewPosition)
@@ -302,6 +298,9 @@ abstract class PagerViewer(
      * Sets the active [chapters] on this pager.
      */
     private fun setChaptersInternal(chapters: ViewerChapters) {
+        // Remove listener so the change in item doesn't trigger it
+        pager.removeOnPageChangeListener(pagerListener)
+
         val forceTransition =
             config.alwaysShowChapterTransition ||
                 adapter.joinedItems.getOrNull(pager.currentItem)?.first is ChapterTransition
@@ -314,6 +313,8 @@ abstract class PagerViewer(
             moveToPage(pages[min(chapters.currChapter.requestedPage, pages.lastIndex)])
             pager.isVisible = true
         }
+
+        pager.addOnPageChangeListener(pagerListener)
     }
 
     /**