lib/strings: allow CA paths in isStorePath

lib/strings.nix

@@ -2434,7 +2434,13 @@ rec {
     if isStringLike x then
       let str = toString x; in
       substring 0 1 str == "/"
-      && dirOf str == storeDir
+      && (dirOf str == storeDir
+        # Match content‐addressed derivations, which _currently_ do not have a
+        # store directory prefix.
+        # This is a workaround for https://github.com/NixOS/nix/issues/12361
+        # which was needed during the experimental phase of ca-derivations and
+        # should be removed once the issue has been resolved.
+        || builtins.match "/[0-9a-z]{52}" str != null)
     else
       false;
 

lib/tests/misc.nix

@@ -537,6 +537,7 @@ runTests {
     expr =
       let goodPath =
             "${builtins.storeDir}/d945ibfx9x185xf04b890y4f9g3cbb63-python-2.7.11";
+          goodCAPath = "/1121rp0gvr1qya7hvy925g5kjwg66acz6sn1ra1hca09f1z5dsab";
       in {
         storePath = isStorePath goodPath;
         storePathDerivation = isStorePath (import ../.. { system = "x86_64-linux"; }).hello;
@@ -545,6 +546,12 @@ runTests {
         nonAbsolute = isStorePath (concatStrings (tail (stringToCharacters goodPath)));
         asPath = isStorePath (/. + goodPath);
         otherPath = isStorePath "/something/else";
+
+        caPath = isStorePath goodCAPath;
+        caPathAppendix = isStorePath
+          "${goodCAPath}/bin/python";
+        caAsPath = isStorePath (/. + goodCAPath);
+
         otherVals = {
           attrset = isStorePath {};
           list = isStorePath [];
@@ -557,6 +564,9 @@ runTests {
       storePathAppendix = false;
       nonAbsolute = false;
       asPath = true;
+      caPath = true;
+      caPathAppendix = false;
+      caAsPath = true;
       otherPath = false;
       otherVals = {
         attrset = false;