3 files changed, 28 insertions, 1 deletions
diff --git a/app/src/main/java/invalid/lena/rsend/Config.kt b/app/src/main/java/invalid/lena/rsend/Config.kt
index 25bf338..a38fbde 100644
--- a/app/src/main/java/invalid/lena/rsend/Config.kt
+++ b/app/src/main/java/invalid/lena/rsend/Config.kt
@@ -57,6 +57,9 @@ object RemoteRules {
         if (remote.hostKey.length > MAX_HOST_KEY_CHARS) return false
         val parts = remote.hostKey.split(' ')
         if (parts.size != 3 || parts.any(String::isEmpty)) return false
+        // Must be exactly the address rsh writes, which is knownhosts.Normalize:
+        // the bare host on port 22, including an IPv6 literal, "[host]:port"
+        // otherwise. A different form here silently stops matching the pin.
         val address = if (remote.port == 22) remote.host else "[${remote.host}]:${remote.port}"
         if (parts[0] != address || parts[1] !in hostKeyTypes) return false
         return try {
@@ -187,6 +190,19 @@ data class Config(
             }
         }
 
+        // overLimit reports why c cannot be persisted, or null. These are the
+        // only save failures a form cannot rule out on its own, so the editors
+        // ask before adding an entry and report the answer. Every other rule
+        // fromJson enforces is already checked field by field; one firing there
+        // is a bug and must throw.
+        fun overLimit(c: Config): String? = when {
+            c.remotes.size > MAX_REMOTES -> "Too many remotes; the limit is $MAX_REMOTES."
+            c.folders.size > MAX_FOLDERS -> "Too many folders; the limit is $MAX_FOLDERS."
+            c.toJson().toString(2).toByteArray(Charsets.UTF_8).size > MAX_CONFIG_BYTES ->
+                "Configuration is too large; the limit is $MAX_CONFIG_BYTES bytes."
+            else -> null
+        }
+
         // legacyShape reports whether o is the pre-0.2 config 0.1.x wrote: one
         // "remote" object instead of a "remotes" array.
         fun legacyShape(o: JSONObject): Boolean =
diff --git a/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt b/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
index 5565bff..47961c1 100644
--- a/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
+++ b/app/src/main/java/invalid/lena/rsend/FolderEditActivity.kt
@@ -161,7 +161,13 @@ class FolderEditActivity : AppCompatActivity() {
         }
         val list = cfg.folders.toMutableList()
         if (index in list.indices) list[index] = f else list.add(f)
-        Config.save(this, cfg.copy(folders = list))
+        val next = cfg.copy(folders = list)
+        val limit = Config.overLimit(next)
+        if (limit != null) {
+            Toast.makeText(this, limit, Toast.LENGTH_LONG).show()
+            return false
+        }
+        Config.save(this, next)
         return true
     }
 
diff --git a/app/src/main/java/invalid/lena/rsend/RemoteActivity.kt b/app/src/main/java/invalid/lena/rsend/RemoteActivity.kt
index 994e233..83f499d 100644
--- a/app/src/main/java/invalid/lena/rsend/RemoteActivity.kt
+++ b/app/src/main/java/invalid/lena/rsend/RemoteActivity.kt
@@ -130,6 +130,11 @@ class RemoteActivity : AppCompatActivity() {
                     "folder \"${b.name.ifEmpty { b.remotePath }}\"."
             return -1
         }
+        val limit = Config.overLimit(next)
+        if (limit != null) {
+            status.text = limit
+            return -1
+        }
         Config.save(this, next)
         Scheduler.apply(this)
         return at