From 84a8b5e9af2df4ed7f7860a6768daf83f72724ca Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Tue, 4 Feb 2014 10:37:10 -0500
Subject: [PATCH] nix-instantiate --eval-only --read-write-mode: Don't depend
 on ordering

Signed-off-by: Shea Levy <shea@shealevy.com>
---
 src/nix-instantiate/nix-instantiate.cc | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/nix-instantiate/nix-instantiate.cc b/src/nix-instantiate/nix-instantiate.cc
index 6a93acf396..e9f1284eb1 100644
--- a/src/nix-instantiate/nix-instantiate.cc
+++ b/src/nix-instantiate/nix-instantiate.cc
@@ -97,23 +97,19 @@ void run(Strings args)
     bool strict = false;
     Strings attrPaths;
     Bindings autoArgs;
+    bool wantsReadWrite = false;
 
     for (Strings::iterator i = args.begin(); i != args.end(); ) {
         string arg = *i++;
 
         if (arg == "-")
             readStdin = true;
-        else if (arg == "--eval-only") {
-            settings.readOnlyMode = true;
+        else if (arg == "--eval-only")
             evalOnly = true;
-        }
-        else if (arg == "--read-write-mode") {
-            settings.readOnlyMode = false;
-        }
-        else if (arg == "--parse-only") {
-            settings.readOnlyMode = true;
+        else if (arg == "--read-write-mode")
+            wantsReadWrite = true;
+        else if (arg == "--parse-only")
             parseOnly = evalOnly = true;
-        }
         else if (arg == "--find-file")
             findFile = true;
         else if (arg == "--attr" || arg == "-A") {
@@ -146,6 +142,9 @@ void run(Strings args)
             files.push_back(arg);
     }
 
+    if (evalOnly && !wantsReadWrite)
+        settings.readOnlyMode = true;
+
     if (attrPaths.empty()) attrPaths.push_back("");
 
     if (findFile) {