Merge branch 'file' into next

RouterOS is suffering a race condition, where a file exists, but its
properties are not (yet) available. This is handled in $WaitForFile.

This passes an interval of zero to $WaitForFile, as does not wait for
the file to exist, but wants to avoid the race only.

global-functions.rsc

@@ -559,6 +559,12 @@
 :set FileGet do={
   :local FileName [ :tostr $1 ];
 
+  :global WaitForFile;
+
+  :if ([ $WaitForFile $FileName 0s ] = false) do={
+    :return false;
+  }
+
   :local FileVal false;
   :do {
     :set FileVal [ /file/get $FileName ];
@@ -1771,14 +1777,26 @@
   :global MAX;
 
   :set FileName [ $CleanFilePath $FileName ];
-  :local Delay ([ $MAX [ $EitherOr $WaitTime 2s ] 100ms ] / 10);
+  :local Delay ([ $MAX [ $EitherOr $WaitTime 2s ] 100ms ] / 9);
 
   :do {
-    :retry {
+    :retry { 
+      :if ([ :len [ /file/find where name=$FileName ] ] = 0) do={
+        :error false;
+      }
+    } delay=$Delay max=10;
+  } on-error={
+    :return false;
+  }
+
+  :while ([ :len [ /file/find where name=$FileName ] ] > 0) do={
+    :do {
       /file/get $FileName;
       :return true;
-    } delay=$Delay max=10;
-  } on-error={ }
+    } on-error={ }
+    :delay $Delay;
+    :set Delay ($Delay * 3 / 2);
+  }
 
   :return false;
 }