Check for sealed namespace in is_installed()

Closes #1378
r-lib · May 24, 2022 · d2f1a7b · d2f1a7b
1 parent 2b472ff
commit d2f1a7b
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/R/session.R b/R/session.R
@@ -74,7 +74,13 @@ detect_installed <- function(info) {
   }
 
   flatten_lgl(pmap(info, function(pkg, cmp, ver) {
-    if (requireNamespace(pkg, quietly = TRUE)) {
+    # Check for sealed namespaces to protect against `is_installed()`
+    # being called from user hooks of `pkg` (#1378)
+    is_fully_loaded <-
+      requireNamespace(pkg, quietly = TRUE) &&
+      env_is_locked(ns_env(pkg))
+
+    if (is_fully_loaded) {
       is_na(ver) || exec(cmp, utils::packageVersion(pkg), ver)
     } else {
       FALSE