app: refuse folder mappings with empty paths

The trailing-slash fix-up turns an empty local path into /, so a blank
folder row would rsync the entire filesystem; an empty remote path
pushes into the rrsync root. Reject both when saving a folder, skip and
log them at run time in case the config was edited by hand, and log why
a sync was skipped when the app is not configured yet.

2 files changed, 16 insertions, 4 deletions

diff --git a/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt b/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
index c61276c..466a859 100644
--- a/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
+++ b/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
@@ -64,13 +64,13 @@ class FolderEditActivity : AppCompatActivity() {
             )
         }
 
-        findViewById<Button>(R.id.save).setOnClickListener { saveFolder(); finish() }
+        findViewById<Button>(R.id.save).setOnClickListener { if (saveFolder()) finish() }
         val del = findViewById<Button>(R.id.removeFolder)
         del.visibility = if (index < 0) View.GONE else View.VISIBLE
         del.setOnClickListener { removeFolder(); finish() }
     }
 
-    private fun saveFolder() {
+    private fun saveFolder(): Boolean {
         val f = Folder(
             name = name.text.toString().trim(),
             local = local.text.toString().trim(),
@@ -78,13 +78,20 @@ class FolderEditActivity : AppCompatActivity() {
             delete = delete.isChecked,
             excludes = excludes.text.toString().split(",").map { it.trim() }.filter { it.isNotEmpty() },
         )
-        if (f.local.isNotEmpty() && !File(f.local).exists()) {
+        // An empty path would rsync / (local) or the rrsync root (remote):
+        // refuse rather than sync the world.
+        if (f.local.isEmpty() || f.remote.isEmpty()) {
+            Toast.makeText(this, "Set both local and remote paths first.", Toast.LENGTH_LONG).show()
+            return false
+        }
+        if (!File(f.local).exists()) {
             Toast.makeText(this, "Warning: local path does not exist yet.", Toast.LENGTH_LONG).show()
         }
         val cfg = Config.load(this)
         val list = cfg.folders.toMutableList()
         if (index in list.indices) list[index] = f else list.add(f)
         Config.save(this, cfg.copy(folders = list))
+        return true
     }
 
     private fun removeFolder() {
diff --git a/app/src/main/java/invalid/lena/rsend/SyncWorker.kt b/app/src/main/java/invalid/lena/rsend/SyncWorker.kt
index f4607ea..a70a3e6 100644
--- a/app/src/main/java/invalid/lena/rsend/SyncWorker.kt
+++ b/app/src/main/java/invalid/lena/rsend/SyncWorker.kt
@@ -30,6 +30,7 @@ class SyncWorker(ctx: Context, params: WorkerParameters) : CoroutineWorker(ctx,
         val startedAt = System.currentTimeMillis()
         val cfg = Config.load(ctx)
         if (cfg.remote.host.isEmpty() || cfg.folders.isEmpty() || !Keys.exists(ctx) || !Keys.pinned(ctx)) {
+            SyncLog(ctx).line("sync skipped: remote, folders, key, or pinned host missing")
             return@withContext Result.success()
         }
 
@@ -54,7 +55,11 @@ class SyncWorker(ctx: Context, params: WorkerParameters) : CoroutineWorker(ctx,
             // Publish progress the dashboard observes (current folder, i of n).
             setProgress(workDataOf(KEY_FOLDER to label, KEY_INDEX to i + 1, KEY_TOTAL to total))
             log.line("=== $label ===")
-            val code = try {
+            // Guard against a hand-edited config: an empty path would rsync /.
+            val code = if (f.local.isEmpty() || f.remote.isEmpty()) {
+                log.line("error: local or remote path not set")
+                1
+            } else try {
                 RsyncRunner.runFolder(ctx, cfg.remote, f, log)
             } catch (e: Exception) {
                 log.line("error: ${e.message}")