Clean up exception handling and retry code

Clean up the exception matching and retry handling code, to unify UI
termination and reduce code duplication.

src/uitext.ml

@@ -1641,6 +1641,15 @@ let rec start interface =
    from here onwards are treated as potentially temporary or recoverable.
    The process does not have to exit if in repeat mode and can try again. *)
 and start2 () =
+  let noRepeat =
+    Prefs.read Uicommon.repeat = `NoRepeat
+      || Prefs.read Uicommon.runtests
+      || Prefs.read Uicommon.testServer
+  in
+  let terminate () =
+    handleException Sys.Break;
+    exit Uicommon.fatalExit
+  in
   begin try
     Uicommon.connectRoots ~displayWaitMessage ();
 
@@ -1664,28 +1673,20 @@ and start2 () =
     (* Put the terminal back in "sane" mode, if necessary, and quit. *)
     restoreTerminal();
     exit exitStatus
-
   with
-    Sys.Break -> begin
-      (* If we've been killed, then die *)
-      handleException Sys.Break;
-      exit Uicommon.fatalExit
-    end
-  | e when breakRepeat e -> begin
+  | Sys.Break -> terminate ()
+  | e when noRepeat || breakRepeat e -> begin
       handleException e;
       exit Uicommon.fatalExit
     end
   | e -> begin
       (* If any other bad thing happened and the -repeat preference is
          set, then restart *)
       handleException e;
-      if Prefs.read Uicommon.repeat = `NoRepeat
-          || Prefs.read Uicommon.runtests then
-        exit Uicommon.fatalExit;
 
       Util.msg "\nRestarting in 10 seconds...\n\n";
-      begin try interruptibleSleep 10 with Sys.Break -> exit Uicommon.fatalExit end;
-      if safeStopRequested () then exit Uicommon.fatalExit else start2 ()
+      begin try interruptibleSleep 10 with Sys.Break -> terminate () end;
+      if safeStopRequested () then terminate () else start2 ()
     end
   end