app: drop --mkpath for compatibility with old remote rsyncs

rsync forwards --mkpath to the remote side when sending, so a remote
rsync older than 3.2.3 (notably stock macOS, whose openrsync is
"rsync 2.6.9 compatible") rejects every sync with "unrecognized
option '--mkpath'".

rsync creates the final component of the destination path on its own,
so flat remote paths keep working everywhere, including the documented
rrsync setup whose root is pre-created. Only a nested remote path with
missing parents now needs a one-time mkdir -p on the server; the log
shows rsync's error when it is missing.

Reported-by: jsvk
Link: https://codeberg.org/0xlena/rsend/pulls/1

1 files changed, 8 insertions, 4 deletions

diff --git a/app/src/main/java/invalid/lena/rsend/RsyncRunner.kt b/app/src/main/java/invalid/lena/rsend/RsyncRunner.kt
index c37e3ce..4d636a6 100644
--- a/app/src/main/java/invalid/lena/rsend/RsyncRunner.kt
+++ b/app/src/main/java/invalid/lena/rsend/RsyncRunner.kt
@@ -11,16 +11,20 @@ import kotlinx.coroutines.launch
 object RsyncRunner {
 
     // args builds the rsync argument vector for one folder. Flags are tuned for
-    // media backup: recursive, preserve mtimes, resume partial files, create
-    // the remote path, and skip the ownership and permission bits that mean
-    // nothing across Android and a server.
+    // media backup: recursive, preserve mtimes, resume partial files, and skip
+    // the ownership and permission bits that mean nothing across Android and a
+    // server.
+    //
+    // No --mkpath: rsync forwards it to the remote when sending, and remotes
+    // older than 3.2.3 (notably stock macOS) reject it. rsync creates the
+    // final component of the destination path on its own; deeper missing
+    // parents need a one-time mkdir on the server (see README).
     fun args(rsh: String, remote: Remote, f: Folder): List<String> {
         val a = ArrayList<String>()
         a.add("-rt")
         a.add("--partial")
         // Abort rather than hang if the network stalls for 5 minutes.
         a.add("--timeout=300")
-        a.add("--mkpath")
         a.add("--no-perms")
         a.add("--no-owner")
         a.add("--no-group")