fix(widget): avoid recycling aliased source bitmap for 2:3 covers (#4850)

Bitmap.createBitmap returns the same immutable instance when the center-crop covers the whole source, which happens for covers that decode to exactly 2:3. writeThumbnail then recycled that instance before createScaledBitmap used it, crashing with "cannot use a recycled source in createBitmap". Guard the recycle the same way the scaled vs cropped case is already guarded, and add an instrumented regression test. Also bundles a pending widget debugging note and a regenerated fastlane README that were staged in the working tree. Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-29 10:13:17 +08:00
parent 5358d85c0b
commit a23427ccc6
4 changed files with 55 additions and 9 deletions
@@ -0,0 +1,49 @@
+package com.readest.native_bridge
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+import java.io.File
+
+/**
+ * Instrumented test (runs on an Android device/emulator).
+ *
+ * Regression for the widget cover crash: a cover that decodes to exactly 2:3
+ * makes the center-crop a no-op, so Bitmap.createBitmap returns the SAME
+ * immutable instance as the source. The pre-fix code recycled the source right
+ * after, then passed the now-recycled bitmap to createScaledBitmap, throwing
+ * "cannot use a recycled source in createBitmap" and killing the app.
+ */
+@RunWith(AndroidJUnit4::class)
+class ReadingWidgetStoreTest {
+    @Test
+    fun writeThumbnail_exact2to3Cover_doesNotCrash() {
+        val ctx = InstrumentationRegistry.getInstrumentation().targetContext
+
+        // 240x360 is exactly 2:3 and small enough to skip downsampling, so the
+        // decoded cover hits the createBitmap same-instance path.
+        val src = Bitmap.createBitmap(240, 360, Bitmap.Config.ARGB_8888)
+        val srcFile = File(ctx.cacheDir, "widget-cover-2x3.png")
+        srcFile.outputStream().use { src.compress(Bitmap.CompressFormat.PNG, 100, it) }
+        src.recycle()
+
+        val hash = "regression2x3"
+        try {
+            // Pre-fix: throws IllegalArgumentException. Post-fix: writes the PNG.
+            ReadingWidgetStore.writeThumbnail(ctx, hash, srcFile.absolutePath, 42)
+
+            val out = File(ReadingWidgetStore.coversDir(ctx), "$hash.png")
+            assertTrue("thumbnail should be written", out.exists())
+            val decoded = BitmapFactory.decodeFile(out.absolutePath)
+            assertNotNull("thumbnail should decode to a valid bitmap", decoded)
+            out.delete()
+        } finally {
+            srcFile.delete()
+        }
+    }
+}
@@ -57,7 +57,11 @@ object ReadingWidgetStore {
        val cropX = (srcW - cropW) / 2
        val cropY = (srcH - cropH) / 2
        val cropped = Bitmap.createBitmap(bitmap, cropX, cropY, cropW, cropH)
-        bitmap.recycle()
+        // createBitmap returns the SAME instance when the crop covers the whole
+        // (immutable) source — i.e. covers already at exactly 2:3. Recycling here
+        // would recycle `cropped` too and crash createScaledBitmap below with
+        // "cannot use a recycled source". Mirror the scaled !== cropped guard.
+        if (cropped !== bitmap) bitmap.recycle()

        // Scale the cropped bitmap to the target size.
        val scaled = Bitmap.createScaledBitmap(cropped, THUMB_WIDTH, THUMB_HEIGHT, true)