Separate flags from positional args with --

This prevents interpreting filenames with leading `-` as flags.

Add a regression test for this behavior.

Fixes https://github.com/ryantm/agenix/issues/325

example/-leading-hyphen-filename.age

@@ -0,0 +1,7 @@
+age-encryption.org/v1
+-> ssh-ed25519 V3XmEA zirqdzZZ1E+sedBn7fbEHq4ntLEkokZ4GctarBBOHXY
+Rvs5YHaAUeCZyNwPedubPcHClWYIuXXWA5zadXPWY6w
+-> ssh-ed25519 KLPP8w BVp4rDkOYSQyn8oVeHFeinSqW+pdVtxBF9+5VM1yORY
+bMwppAi8Nhz0328taU4AzUkTVyWtSLvFZG6c5W/Fs78
+--- xCbqLhXAcOziO2wmbjTiSQfZvt5Rlsc4SCvF+iEzpQA
+ôKB£î/²ZÅÈrÙ%
¾à4¡´—Mq5×Ô_ÌÂÝ’‹†ã„Ò11ܨqM;& ¢‡LríÂÒføû”]>N

example/secrets.nix

@@ -5,4 +5,5 @@ in {
   "secret1.age".publicKeys = [user1 system1];
   "secret2.age".publicKeys = [user1];
   "passwordfile-user1.age".publicKeys = [user1 system1];
+  "-leading-hyphen-filename.age".publicKeys = [user1 system1];
 }

pkgs/agenix.sh

@@ -105,11 +105,11 @@ RULES=${RULES:-./secrets.nix}
 function cleanup {
     if [ -n "${CLEARTEXT_DIR+x}" ]
     then
-        rm -rf "$CLEARTEXT_DIR"
+        rm -rf -- "$CLEARTEXT_DIR"
     fi
     if [ -n "${REENCRYPTED_DIR+x}" ]
     then
-        rm -rf "$REENCRYPTED_DIR"
+        rm -rf -- "$REENCRYPTED_DIR"
     fi
 }
 trap "cleanup" 0 2 3 15
@@ -141,7 +141,7 @@ function decrypt {
           err "No identity found to decrypt $FILE. Try adding an SSH key at $HOME/.ssh/id_rsa or $HOME/.ssh/id_ed25519 or using the --identity flag to specify a file."
         fi
 
-        @ageBin@ "${DECRYPT[@]}" "$FILE" || exit 1
+        @ageBin@ "${DECRYPT[@]}" -- "$FILE" || exit 1
     fi
 }
 
@@ -150,14 +150,14 @@ function edit {
     KEYS=$(keys "$FILE") || exit 1
 
     CLEARTEXT_DIR=$(@mktempBin@ -d)
-    CLEARTEXT_FILE="$CLEARTEXT_DIR/$(basename "$FILE")"
+    CLEARTEXT_FILE="$CLEARTEXT_DIR/$(basename -- "$FILE")"
     DEFAULT_DECRYPT+=(-o "$CLEARTEXT_FILE")
 
     decrypt "$FILE" "$KEYS" || exit 1
 
-    [ ! -f "$CLEARTEXT_FILE" ] || cp "$CLEARTEXT_FILE" "$CLEARTEXT_FILE.before"
+    [ ! -f "$CLEARTEXT_FILE" ] || cp -- "$CLEARTEXT_FILE" "$CLEARTEXT_FILE.before"
 
-    [ -t 0 ] || EDITOR='cp /dev/stdin'
+    [ -t 0 ] || EDITOR='cp -- /dev/stdin'
 
     $EDITOR "$CLEARTEXT_FILE"
 
@@ -166,7 +166,7 @@ function edit {
       warn "$FILE wasn't created."
       return
     fi
-    [ -f "$FILE" ] && [ "$EDITOR" != ":" ] && @diffBin@ -q "$CLEARTEXT_FILE.before" "$CLEARTEXT_FILE" && warn "$FILE wasn't changed, skipping re-encryption." && return
+    [ -f "$FILE" ] && [ "$EDITOR" != ":" ] && @diffBin@ -q -- "$CLEARTEXT_FILE.before" "$CLEARTEXT_FILE" && warn "$FILE wasn't changed, skipping re-encryption." && return
 
     ENCRYPT=()
     while IFS= read -r key
@@ -177,15 +177,15 @@ function edit {
     done <<< "$KEYS"
 
     REENCRYPTED_DIR=$(@mktempBin@ -d)
-    REENCRYPTED_FILE="$REENCRYPTED_DIR/$(basename "$FILE")"
+    REENCRYPTED_FILE="$REENCRYPTED_DIR/$(basename -- "$FILE")"
 
     ENCRYPT+=(-o "$REENCRYPTED_FILE")
 
     @ageBin@ "${ENCRYPT[@]}" <"$CLEARTEXT_FILE" || exit 1
 
-    mkdir -p "$(dirname "$FILE")"
+    mkdir -p -- "$(dirname -- "$FILE")"
 
-    mv -f "$REENCRYPTED_FILE" "$FILE"
+    mv -f -- "$REENCRYPTED_FILE" "$FILE"
 }
 
 function rekey {

test/integration.nix

@@ -24,8 +24,9 @@ pkgs.nixosTest {
 
     services.openssh.enable = true;
 
-    age.secrets.passwordfile-user1 = {
-      file = ../example/passwordfile-user1.age;
+    age.secrets = {
+      passwordfile-user1.file = ../example/passwordfile-user1.age;
+      leading-hyphen.file = ../example/-leading-hyphen-filename.age;
     };
 
     age.identityPaths = options.age.identityPaths.default ++ ["/etc/ssh/this_key_wont_exist"];
@@ -71,6 +72,7 @@ pkgs.nixosTest {
     user = "user1";
     password = "password1234";
     secret2 = "world!";
+    hyphen-secret = "filename started with hyphen";
   in ''
     system1.wait_for_unit("multi-user.target")
     system1.wait_until_succeeds("pgrep -f 'agetty.*tty1'")
@@ -92,6 +94,8 @@ pkgs.nixosTest {
     system1.wait_for_file("/tmp/2")
     assert "${secret2}" in system1.succeed("cat /tmp/2")
 
+    assert "${hyphen-secret}" in system1.succeed("cat /run/agenix/leading-hyphen")
+
     userDo = lambda input : f"sudo -u user1 -- bash -c 'set -eou pipefail; cd /tmp/secrets; {input}'"
 
     before_hash = system1.succeed(userDo('sha256sum passwordfile-user1.age')).split()