Re-allow inputs.x.url = "/path/to/file"

src/libexpr/flake/flake.cc

@@ -155,7 +155,7 @@ static FlakeInput parseFlakeInput(EvalState & state,
         if (!attrs.empty())
             throw Error("unexpected flake input attribute '%s', at %s", attrs.begin()->first, pos);
         if (url)
-            input.ref = parseFlakeRef(*url, baseDir, true);
+            input.ref = parseFlakeRef(*url, baseDir, true, input.isFlake);
     }
 
     if (!input.follows && !input.ref)
@@ -194,8 +194,8 @@ static Flake getFlake(
         state, originalRef, allowLookup, flakeCache);
 
     // Guard against symlink attacks.
-    auto flakeDir = canonPath(sourceInfo.actualPath + "/" + lockedRef.subdir);
+    auto flakeDir = canonPath(sourceInfo.actualPath + "/" + lockedRef.subdir, true);
-    auto flakeFile = canonPath(flakeDir + "/flake.nix");
+    auto flakeFile = canonPath(flakeDir + "/flake.nix", true);
     if (!isInDir(flakeFile, sourceInfo.actualPath))
         throw Error("'flake.nix' file of flake '%s' escapes from '%s'",
             lockedRef, state.store->printStorePath(sourceInfo.storePath));
@@ -570,7 +570,7 @@ LockedFlake lockFlake(
         };
 
         // Bring in the current ref for relative path resolution if we have it
-        auto parentPath = canonPath(flake.sourceInfo->actualPath + "/" + flake.lockedRef.subdir);
+        auto parentPath = canonPath(flake.sourceInfo->actualPath + "/" + flake.lockedRef.subdir, true);
 
         computeLocks(
             flake.inputs, newLockFile.root, {},

src/libexpr/flake/flakeref.cc

@@ -48,9 +48,12 @@ FlakeRef FlakeRef::resolve(ref<Store> store) const
 }
 
 FlakeRef parseFlakeRef(
-    const std::string & url, const std::optional<Path> & baseDir, bool allowMissing)
+    const std::string & url,
+    const std::optional<Path> & baseDir,
+    bool allowMissing,
+    bool isFlake)
 {
-    auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir, allowMissing);
+    auto [flakeRef, fragment] = parseFlakeRefWithFragment(url, baseDir, allowMissing, isFlake);
     if (fragment != "")
         throw Error("unexpected fragment '%s' in flake reference '%s'", fragment, url);
     return flakeRef;
@@ -67,7 +70,10 @@ std::optional<FlakeRef> maybeParseFlakeRef(
 }
 
 std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
-    const std::string & url, const std::optional<Path> & baseDir, bool allowMissing)
+    const std::string & url,
+    const std::optional<Path> & baseDir,
+    bool allowMissing,
+    bool isFlake)
 {
     using namespace fetchers;
 
@@ -112,7 +118,9 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
                to 'baseDir'). If so, search upward to the root of the
                repo (i.e. the directory containing .git). */
 
-            path = absPath(path, baseDir, true);
+            path = absPath(path, baseDir);
+
+            if (isFlake) {
 
                 if (!S_ISDIR(lstat(path).st_mode))
                     throw BadURL("path '%s' is not a flake (because it's not a directory)", path);
@@ -153,6 +161,7 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
                     subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
                     flakeRoot = dirOf(flakeRoot);
                 }
+            }
 
         } else {
             if (!hasPrefix(path, "/"))

src/libexpr/flake/flakeref.hh

@@ -62,13 +62,19 @@ struct FlakeRef
 std::ostream & operator << (std::ostream & str, const FlakeRef & flakeRef);
 
 FlakeRef parseFlakeRef(
-    const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
+    const std::string & url,
+    const std::optional<Path> & baseDir = {},
+    bool allowMissing = false,
+    bool isFlake = true);
 
 std::optional<FlakeRef> maybeParseFlake(
     const std::string & url, const std::optional<Path> & baseDir = {});
 
 std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
-    const std::string & url, const std::optional<Path> & baseDir = {}, bool allowMissing = false);
+    const std::string & url,
+    const std::optional<Path> & baseDir = {},
+    bool allowMissing = false,
+    bool isFlake = true);
 
 std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment(
     const std::string & url, const std::optional<Path> & baseDir = {});

tests/flakes.sh

@@ -249,6 +249,14 @@ cat > $flake3Dir/flake.nix <<EOF
       url = git+file://$nonFlakeDir;
       flake = false;
     };
+    nonFlakeFile = {
+      url = path://$nonFlakeDir/README.md;
+      flake = false;
+    };
+    nonFlakeFile2 = {
+      url = "$nonFlakeDir/README.md";
+      flake = false;
+    };
   };
 
   description = "Fnord";
@@ -265,6 +273,8 @@ cat > $flake3Dir/flake.nix <<EOF
         dummy2 = builtins.readFile (builtins.path { name = "source"; path = inputs.flake1; filter = path: type: baseNameOf path == "simple.nix"; } + "/simple.nix");
         buildCommand = ''
           cat \${inputs.nonFlake}/README.md > \$out
+          [[ \$(cat \${inputs.nonFlake}/README.md) = \$(cat \${inputs.nonFlakeFile}) ]]
+          [[ \${inputs.nonFlakeFile} = \${inputs.nonFlakeFile2} ]]
         '';
       };
   };