music: fix music loading crash with weird genres

Fix an issue where genres consisting only of whitespace crash the genre
parser, and thus the music loader.

Band-aid this by moving the trimming code out of splitEscaped and into
maybeParseSeparators. In a future version I'll need to figure out how I
want to handle these weird edge cases.

CHANGELOG.md

@@ -51,7 +51,7 @@ audio focus was lost
 - Switched to issue forms
 - Completed migration to reactive playback system
 - Refactor music backends into a unified chain of extractors
-- Add bluetooth connection reciever (No functionality in app yet)
+- Add bluetooth connection receiver (No functionality in app yet)
 
 ## 2.6.4
 

app/src/main/java/org/oxycblt/auxio/music/extractor/CacheExtractor.kt

@@ -283,8 +283,8 @@ private class CacheDatabase(context: Context) :
                 raw.albumMusicBrainzId = cursor.getStringOrNull(albumMusicBrainzIdIndex)
                 raw.albumName = cursor.getString(albumNameIndex)
                 raw.albumSortName = cursor.getStringOrNull(albumSortNameIndex)
-                cursor.getStringOrNull(albumTypesIndex)?.parseSQLMultiValue()?.let {
-                    raw.albumTypes = it
+                cursor.getStringOrNull(albumTypesIndex)?.let {
+                    raw.albumTypes = it.parseSQLMultiValue()
                 }
 
                 cursor.getStringOrNull(artistMusicBrainzIdsIndex)?.let {
@@ -387,7 +387,8 @@ private class CacheDatabase(context: Context) :
      * @return A list of strings corresponding to the delimited values present within the original
      * string. Escaped delimiters are converted back into their normal forms.
      */
-    private fun String.parseSQLMultiValue() = splitEscaped { it == ';' }
+    private fun String.parseSQLMultiValue() =
+        splitEscaped { it == ';' }
 
     /** Defines the columns used in this database. */
     private object Columns {

app/src/main/java/org/oxycblt/auxio/music/extractor/MetadataExtractor.kt

@@ -187,8 +187,8 @@ class Task(context: Context, private val raw: Song.Raw) {
                     // Map TXXX frames differently so we can specifically index by their
                     // descriptions.
                     val id = tag.description?.let { "TXXX:${it.sanitize()}" } ?: tag.id.sanitize()
-                    val values = tag.values.map { it.sanitize() }
-                    if (values.isNotEmpty() && values.all { it.isNotEmpty() }) {
+                    val values = tag.values.map { it.sanitize() }.filter { it.isNotEmpty() }
+                    if (values.isNotEmpty()) {
                         id3v2Tags[id] = values
                     }
                 }

app/src/main/java/org/oxycblt/auxio/music/extractor/ParsingUtil.kt

@@ -21,6 +21,7 @@ import androidx.core.text.isDigitsOnly
 import java.util.UUID
 import org.oxycblt.auxio.music.Date
 import org.oxycblt.auxio.settings.Settings
+import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.nonZeroOrNull
 
 /**
@@ -88,7 +89,7 @@ inline fun String.splitEscaped(selector: (Char) -> Boolean): List<String> {
         if (selector(a)) {
             // Non-escaped separator, split the string here, making sure any stray whitespace
             // is removed.
-            split.add(currentString.trim())
+            split.add(currentString)
             currentString = ""
             i++
             continue
@@ -107,8 +108,8 @@ inline fun String.splitEscaped(selector: (Char) -> Boolean): List<String> {
     }
 
     if (currentString.isNotEmpty()) {
-        // Had an in-progress split string that is now terminated, add it..
-        split.add(currentString.trim())
+        // Had an in-progress split string that is now terminated, add it.
+        split.add(currentString)
     }
 
     return split
@@ -126,7 +127,7 @@ fun List<String>.parseMultiValue(settings: Settings) =
         get(0).maybeParseSeparators(settings)
     } else {
         // Nothing to do.
-        this
+        this.map { it.trim() }
     }
 
 /**
@@ -137,7 +138,7 @@ fun List<String>.parseMultiValue(settings: Settings) =
 fun String.maybeParseSeparators(settings: Settings): List<String> {
     // Get the separators the user desires. If null, there's nothing to do.
     val separators = settings.musicSeparators ?: return listOf(this)
-    return splitEscaped { separators.contains(it) }
+    return splitEscaped { separators.contains(it) }.map { it.trim() }
 }
 
 /**
@@ -179,20 +180,20 @@ fun String.parseId3GenreNames(settings: Settings) =
  * @return A named genre if the field is a valid integer, "Cover" or "Remix" if the field is
  * "CR"/"RX" respectively, and nothing if the field is not a valid ID3v1 integer genre.
  */
-private fun String.parseId3v1Genre(): String? =
-    when {
+private fun String.parseId3v1Genre(): String? {
     // ID3v1 genres are a plain integer value without formatting, so in that case
-        // try to index the genre table with such.
-        isDigitsOnly() -> GENRE_TABLE.getOrNull(toInt())
-
+    // try to index the genre table with such. If this fails, then try to compare it
+    // to some other hard-coded values.
+    val numeric = toIntOrNull() ?: return when (this) {
         // CR and RX are not technically ID3v1, but are formatted similarly to a plain number.
-        this == "CR" -> "Cover"
-        this == "RX" -> "Remix"
-
-        // Current name is fine.
+        "CR" -> "Cover"
+        "RX" -> "Remix"
         else -> null
     }
 
+    return GENRE_TABLE.getOrNull(numeric)
+}
+
 /**
  * A [Regex] that implements parsing for ID3v2's genre format. Derived from mutagen:
  * https://github.com/quodlibet/mutagen