Merge pull request #5771 from edolstra/single-file-flake-inputs

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

4 files changed, 65 insertions, 40 deletions

diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index 33d253eee..f598400fc 100644
--- a/src/libexpr/flake/flake.cc
+++ b/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 flakeFile = canonPath(flakeDir + "/flake.nix");
+    auto flakeDir = canonPath(sourceInfo.actualPath + "/" + lockedRef.subdir, true);
+    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, {},
diff --git a/src/libexpr/flake/flakeref.cc b/src/libexpr/flake/flakeref.cc
index 29128d789..c3b74e0fe 100644
--- a/src/libexpr/flake/flakeref.cc
+++ b/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;
 
@@ -112,46 +118,49 @@ 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 (!S_ISDIR(lstat(path).st_mode))
-                throw BadURL("path '%s' is not a flake (because it's not a directory)", path);
+            if (isFlake) {
 
-            if (!allowMissing && !pathExists(path + "/flake.nix"))
-                throw BadURL("path '%s' is not a flake (because it doesn't contain a 'flake.nix' file)", path);
+                if (!S_ISDIR(lstat(path).st_mode))
+                    throw BadURL("path '%s' is not a flake (because it's not a directory)", path);
 
-            auto flakeRoot = path;
-            std::string subdir;
+                if (!allowMissing && !pathExists(path + "/flake.nix"))
+                    throw BadURL("path '%s' is not a flake (because it doesn't contain a 'flake.nix' file)", path);
 
-            while (flakeRoot != "/") {
-                if (pathExists(flakeRoot + "/.git")) {
-                    auto base = std::string("git+file://") + flakeRoot;
+                auto flakeRoot = path;
+                std::string subdir;
 
-                    auto parsedURL = ParsedURL{
-                        .url = base, // FIXME
-                        .base = base,
-                        .scheme = "git+file",
-                        .authority = "",
-                        .path = flakeRoot,
-                        .query = decodeQuery(match[2]),
-                    };
+                while (flakeRoot != "/") {
+                    if (pathExists(flakeRoot + "/.git")) {
+                        auto base = std::string("git+file://") + flakeRoot;
 
-                    if (subdir != "") {
-                        if (parsedURL.query.count("dir"))
-                            throw Error("flake URL '%s' has an inconsistent 'dir' parameter", url);
-                        parsedURL.query.insert_or_assign("dir", subdir);
-                    }
+                        auto parsedURL = ParsedURL{
+                            .url = base, // FIXME
+                            .base = base,
+                            .scheme = "git+file",
+                            .authority = "",
+                            .path = flakeRoot,
+                            .query = decodeQuery(match[2]),
+                        };
 
-                    if (pathExists(flakeRoot + "/.git/shallow"))
-                        parsedURL.query.insert_or_assign("shallow", "1");
+                        if (subdir != "") {
+                            if (parsedURL.query.count("dir"))
+                                throw Error("flake URL '%s' has an inconsistent 'dir' parameter", url);
+                            parsedURL.query.insert_or_assign("dir", subdir);
+                        }
 
-                    return std::make_pair(
-                        FlakeRef(Input::fromURL(parsedURL), get(parsedURL.query, "dir").value_or("")),
-                        fragment);
-                }
+                        if (pathExists(flakeRoot + "/.git/shallow"))
+                            parsedURL.query.insert_or_assign("shallow", "1");
 
-                subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
-                flakeRoot = dirOf(flakeRoot);
+                        return std::make_pair(
+                            FlakeRef(Input::fromURL(parsedURL), get(parsedURL.query, "dir").value_or("")),
+                            fragment);
+                    }
+
+                    subdir = std::string(baseNameOf(flakeRoot)) + (subdir.empty() ? "" : "/" + subdir);
+                    flakeRoot = dirOf(flakeRoot);
+                }
             }
 
         } else {
diff --git a/src/libexpr/flake/flakeref.hh b/src/libexpr/flake/flakeref.hh
index 0292eb210..1fddfd9a0 100644
--- a/src/libexpr/flake/flakeref.hh
+++ b/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 = {});
diff --git a/tests/flakes.sh b/tests/flakes.sh
index 20966ab2a..942d07010 100644
--- a/tests/flakes.sh
+++ b/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} ]]
         '';
       };
   };