From 983efdbde47bd0ecaff866d43c3155761574c112 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <theophane.hufschmitt@tweag.io>
Date: Tue, 21 Jun 2022 14:08:18 +0200
Subject: [PATCH] Forbid the tilde expansion in pure eval mode

Fix #6684
---
 src/libexpr/parser.y | 6 ++++++
 tests/pure-eval.sh   | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 8cbc2da4d..7c9b5a2db 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -520,6 +520,12 @@ path_start
     $$ = new ExprPath(path);
   }
   | HPATH {
+    if (evalSettings.pureEval) {
+        throw Error(
+            "the path '%s' can not be resolved in pure mode",
+            std::string_view($1.p, $1.l)
+        );
+    }
     Path path(getHome() + std::string($1.p + 1, $1.l - 1));
     $$ = new ExprPath(path);
   }
diff --git a/tests/pure-eval.sh b/tests/pure-eval.sh
index 1a4568ea6..b83ab8afe 100644
--- a/tests/pure-eval.sh
+++ b/tests/pure-eval.sh
@@ -30,3 +30,5 @@ nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ x = "foo" + "
 
 rm -rf $TEST_ROOT/eval-out
 (! nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ "." = "bla"; }')
+
+(! nix eval --expr '~/foo')