[#606] Fix BlockHeight read from CompactBlockStore

sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/CompactBlockProcessor.kt

@@ -304,13 +304,15 @@ class CompactBlockProcessor internal constructor(
             ProcessorInfo(
                 networkBlockHeight = downloader.getLatestBlockHeight(),
                 lastScannedHeight = getLastScannedHeight(),
-                lastDownloadedHeight = BlockHeight.new(
-                    network,
-                    max(
-                        getLastDownloadedHeight().value,
-                        lowerBoundHeight.value - 1
+                lastDownloadedHeight = getLastDownloadedHeight()?.let {
+                    BlockHeight.new(
+                        network,
+                        max(
+                            it.value,
+                            lowerBoundHeight.value - 1
+                        )
                     )
-                ),
+                },
                 lastDownloadRange = null,
                 lastScanRange = null
             ).let { initialInfo ->
@@ -574,7 +576,6 @@ class CompactBlockProcessor internal constructor(
                         progress = (i / batches.toFloat() * 100).roundToInt()
                         _progress.send(progress)
                         val lastDownloadedHeight = downloader.getLastDownloadedHeight()
-                            .takeUnless { it < network.saplingActivationHeight }
                         updateProgress(lastDownloadedHeight = lastDownloadedHeight)
                         downloadedBlockHeight = end
                     }

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/block/CompactBlockDbStore.kt

@@ -11,7 +11,6 @@ import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.type.ZcashNetwork
 import cash.z.wallet.sdk.rpc.CompactFormats
 import kotlinx.coroutines.withContext
-import kotlin.math.max
 
 /**
  * An implementation of CompactBlockStore that persists information to a database in the given
@@ -24,7 +23,9 @@ class CompactBlockDbStore private constructor(
 
     private val cacheDao = cacheDb.compactBlockDao()
 
-    override suspend fun getLatestHeight(): BlockHeight = BlockHeight.new(network, max(0L, cacheDao.latestBlockHeight()))
+    override suspend fun getLatestHeight(): BlockHeight? = runCatching {
+        BlockHeight.new(network, cacheDao.latestBlockHeight())
+    }.getOrNull()
 
     override suspend fun findCompactBlock(height: BlockHeight): CompactFormats.CompactBlock? =
         cacheDao.findCompactBlock(height.value)?.let { CompactFormats.CompactBlock.parseFrom(it) }

sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/block/CompactBlockStore.kt

@@ -12,7 +12,7 @@ interface CompactBlockStore {
      *
      * @return the latest block height.
      */
-    suspend fun getLatestHeight(): BlockHeight
+    suspend fun getLatestHeight(): BlockHeight?
 
     /**
      * Fetch the compact block for the given height, if it exists.