fix(dash): [PKG-DASH-SEEK-01] recover paused boundary seeks in SDK 4.5.2

test/browser/dash-seek-diagnostics.js

@@ -0,0 +1,54 @@
+// Page-only counterfactuals, called after a failed SDK assertion. Never production recovery.
+
+export function probeBufferGetter() {
+  const dash = window.art?.dash || window.nativeDash
+  const video = window.art?.video || window.nativeVideo
+  const before = window.dashBuffers.snapshot()
+  const records = []
+  window.dashGetterRestores = []
+  for (const processor of dash.getActiveStream().getProcessors()) {
+    const buffer = processor.getBufferController()
+    const original = buffer.getBufferLevel
+    const record = { type: processor.getType(), reads: 0, adjusted: 0 }
+    const wrapped = function (...args) {
+      const cached = Reflect.apply(original, this, args)
+      record.reads++
+      const time = video.currentTime
+      const range = buffer.getRangeAt(time)
+      if (video.seeking && cached > 0 && (!range || range.end <= time) && !buffer.getIsPruningInProgress() && buffer.getAllRangesWithSafetyFactor(time).length === 0) {
+        record.adjusted++
+        return 0
+      }
+      return cached
+    }
+    buffer.getBufferLevel = wrapped
+    records.push(record)
+    window.dashGetterRestores.push(() => {
+      if (buffer.getBufferLevel === wrapped)
+        buffer.getBufferLevel = original
+    })
+  }
+  window.dashGetterRecords = records
+  return { before, mode: 'conditional-buffer-getter', acceptance: false }
+}
+
+export function probeBufferMetric() {
+  const dash = window.art?.dash || window.nativeDash
+  const video = window.art?.video || window.nativeVideo
+  const metrics = dash.getDashMetrics()
+  const before = window.dashBuffers.snapshot()
+  const settings = JSON.stringify(dash.getSettings())
+  const records = []
+  for (const processor of dash.getActiveStream().getProcessors()) {
+    const type = processor.getType()
+    const buffer = processor.getBufferController()
+    const time = video.currentTime
+    const cached = metrics.getCurrentBufferLevel(type)
+    const range = buffer.getRangeAt(time)
+    if (video.seeking && cached > 0 && (!range || range.end <= time) && !buffer.getIsPruningInProgress() && buffer.getAllRangesWithSafetyFactor(time).length === 0) {
+      metrics.addBufferLevel(type, new Date(), 0)
+      records.push({ type, cached, corrected: metrics.getCurrentBufferLevel(type), time, range })
+    }
+  }
+  return { before, mode: 'measured-empty-buffer-metric', acceptance: false, records, afterMetric: window.dashBuffers.snapshot(), settingsUnchanged: settings === JSON.stringify(dash.getSettings()) }
+}