Handle relative git-url-paths correctly when --directory

lib/src/command/add.dart

@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:path/path.dart' as p;
+import 'package:pub/src/source/path.dart';
 import 'package:pub_semver/pub_semver.dart';
 import 'package:yaml/yaml.dart';
 
@@ -311,25 +313,45 @@ class AddCommand extends PubCommand {
       if (gitUrl == null) {
         usageException('The `--git-url` is required for git dependencies.');
       }
+      Uri parsed;
+      try {
+        parsed = Uri.parse(gitUrl);
+      } on FormatException catch (e) {
+        usageException('The --git-url must be a valid url: ${e.message}.');
+      }
+      final urlRelativeToEntrypoint = parsed.isAbsolute
+          ? parsed.toString()
+          :
+          // Turn the relative url from current working directory into a relative
+          // url from the entrypoint.
+          p.url.relative(
+              p.url.join(Uri.file(p.absolute(p.current)).toString(),
+                  parsed.toString()),
+              from: p.toUri(p.absolute(entrypoint.root.dir)).toString());
 
       /// Process the git options to return the simplest representation to be
       /// added to the pubspec.
       if (gitRef == null && gitPath == null) {
-        git = gitUrl;
+        git = urlRelativeToEntrypoint;
       } else {
-        git = {'url': gitUrl, 'ref': gitRef, 'path': gitPath};
+        git = {'url': urlRelativeToEntrypoint, 'ref': gitRef, 'path': gitPath};
         git.removeWhere((key, value) => value == null);
       }
 
       packageRange = cache.sources['git']
-          .parseRef(packageName, git)
+          .parseRef(packageName, git, containingPath: entrypoint.pubspecPath)
           .withConstraint(constraint ?? VersionConstraint.any);
       pubspecInformation = {'git': git};
     } else if (path != null) {
+      final relativeToEntryPoint = p.isRelative(path)
+          ? PathSource.relativePathWithPosixSeparators(
+              p.relative(path, from: entrypoint.root.dir))
+          : path;
       packageRange = cache.sources['path']
-          .parseRef(packageName, path, containingPath: entrypoint.pubspecPath)
+          .parseRef(packageName, relativeToEntryPoint,
+              containingPath: entrypoint.pubspecPath)
           .withConstraint(constraint ?? VersionConstraint.any);
-      pubspecInformation = {'path': path};
+      pubspecInformation = {'path': relativeToEntryPoint};
     } else if (sdk != null) {
       packageRange = cache.sources['sdk']
           .parseRef(packageName, sdk)

lib/src/global_packages.dart

@@ -90,9 +90,14 @@ class GlobalPackages {
     // dependencies. Their executables shouldn't be cached, and there should
     // be a mechanism for redoing dependency resolution if a path pubspec has
     // changed (see also issue 20499).
+    PackageRef ref;
+    try {
+      ref = cache.git.source.parseRef(name, {'url': repo}, containingPath: '.');
+    } on FormatException catch (e) {
+      throw ApplicationException(e.message);
+    }
     await _installInCache(
-        cache.git.source
-            .refFor(name, repo)
+        ref
             .withConstraint(VersionConstraint.any)
             .withFeatures(features ?? const {}),
         executables,
@@ -282,7 +287,8 @@ To recompile executables, first run `global deactivate ${dep.name}`.
     var oldPath = p.join(_directory, '$package.lock');
     if (fileExists(oldPath)) deleteEntry(oldPath);
 
-    writeTextFile(_getLockFilePath(package), lockFile.serialize(cache.rootDir));
+    writeTextFile(_getLockFilePath(package),
+        lockFile.serialize(p.join(_directory, package)));
   }
 
   /// Shows the user the currently active package with [name], if any.