Fix a source of VFS inconsistencies (#4155)

CouchDB is using ICU algorithm for views and mango requests. It can be
surprizing, and it was the source of a bug in the stack. When a
directory 'EDF' is trashed, and a directory 'EDF⚡️' was nearby, the path
of this directory can be incorrectly modified to be put in the trash.

The system test 'filepath_operations.rb' was restored from
a6a442b, and updated to test this new
case.

model/vfs/couchdb_indexer.go

@@ -149,10 +149,10 @@ func (c *couchdbIndexer) prepareFileDoc(doc *FileDoc) error {
 
 func (c *couchdbIndexer) DirSize(doc *DirDoc) (int64, error) {
 	start := doc.Fullpath + "/"
-	stop := doc.Fullpath + "0" // 0 is the next ascii character after /
+	stop := doc.Fullpath + "/\ufff0"
 	if doc.DocID == consts.RootDirID {
 		start = "/"
-		stop = "0"
+		stop = "/\ufff0"
 	}
 
 	// Find the subdirectories
@@ -362,7 +362,7 @@ func (c *couchdbIndexer) MoveDir(oldpath, newpath string) error {
 	// We limit the stack to 128 bulk updates to avoid infinite loops, as we
 	// had a case in the past.
 	start := oldpath + "/"
-	stop := oldpath + "0" // 0 is the next ascii character after /
+	stop := oldpath + "/\ufff0"
 	for i := 0; i < 128; i++ {
 		// The simple selector mango.StartWith can have some issues when
 		// renaming a folder to the same name, but with a different unicode

tests/system/lib/folder.rb

@@ -111,7 +111,8 @@ def save(inst)
       accept: "application/vnd.api+json",
       authorization: "Bearer #{inst.token_for doctype}"
     }
-    res = inst.client["/files/#{dir_id}?Type=directory&Name=#{name}"].post nil, opts
+    encoded_name = URI.encode_www_form_component(name)
+    res = inst.client["/files/#{dir_id}?Type=directory&Name=#{encoded_name}"].post nil, opts
     j = JSON.parse(res.body)["data"]
     @couch_id = j["id"]
     @couch_rev = j["rev"]

tests/system/tests/filepath_operations.rb

@@ -0,0 +1,68 @@
+require_relative '../boot'
+require 'minitest/autorun'
+require 'pry-rescue/minitest' unless ENV['CI']
+
+describe "The VFS" do
+  it "is able to deal with special cases on filepaths (encoding, case sensitivity)" do
+    Helpers.scenario "filepath_operations"
+    Helpers.start_mailhog
+
+    # Create the instance
+    inst = Instance.create name: "Alice"
+
+    # Create a folder
+    dirname = "this"
+    folder = Folder.create inst, name: dirname
+    folder.couch_id.wont_be_empty
+    sub = Folder.create inst, dir_id: folder.couch_id
+    3.times do
+      CozyFile.create inst, dir_id: sub.couch_id
+      CozyFile.create inst, dir_id: folder.couch_id
+    end
+
+    # Create a folder with the same name, but not the same case
+    other = Folder.create inst, name: dirname.upcase
+    other.couch_id.wont_be_empty
+    4.times do
+      CozyFile.create inst, dir_id: other.couch_id
+    end
+    other.remove inst
+    assert_equal inst.fsck, []
+
+    # Trying stupids tricks
+    before = File.join Helpers.current_dir, inst.domain
+    # Renaming to the same name
+    folder.rename inst, "that" rescue nil
+    # Moving inside its-self
+    folder.move_to inst, folder.couch_id rescue nil
+    # Moving inside a sub-directory
+    folder.move_to inst, sub.couch_id rescue nil
+    after = File.join Helpers.current_dir, inst.domain
+    diff = Helpers.fsdiff before, after
+    diff.must_be_empty
+    assert_equal inst.fsck, []
+
+    # Play with NFC and NFD unicode normalization
+    ["Pièces pour ampèremètre", "Diplômes", "Reçus"].each do |name|
+      nfc = name.unicode_normalize(:nfc)
+      nfd = name.unicode_normalize(:nfd)
+      folder.rename inst, nfc
+      assert_equal inst.fsck, []
+      folder.rename inst, nfd
+      assert_equal inst.fsck, []
+      folder.rename inst, nfc
+      assert_equal inst.fsck, []
+    end
+
+    folder.remove inst
+    Folder.clear_trash inst
+
+    # Emojis can be tricky too
+    folder = Folder.create inst, name: "EDF"
+    Folder.create inst, name: "EDF⚡️"
+    folder.remove inst
+    assert_equal inst.fsck, []
+
+    inst.remove
+  end
+end