From c9d36f1e402e32a7df25764e580ada0b6b505241 Mon Sep 17 00:00:00 2001
From: Morgan Bazalgette <git@howl.moe>
Date: Thu, 27 Sep 2018 10:20:49 +0200
Subject: [PATCH] wip

Signed-off-by: Morgan Bazalgette <git@howl.moe>
---
 config/config.go                 | 33 +++++++++++++++++++++++++++++---
 plumbing/format/config/option.go | 10 ++++++++--
 worktree_status.go               | 21 +++++++++++++++++++-
 3 files changed, 58 insertions(+), 6 deletions(-)

diff --git a/config/config.go b/config/config.go
index a637f6d70..7222c5c05 100644
--- a/config/config.go
+++ b/config/config.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"sort"
 	"strconv"
+	"strings"
 
 	format "gopkg.in/src-d/go-git.v4/plumbing/format/config"
 )
@@ -43,6 +44,10 @@ type Config struct {
 		// CommentChar is the character indicating the start of a
 		// comment for commands like commit and tag
 		CommentChar string
+		// FileMode is normally set to true to tell git to respect and store
+		// the executable bit, but it may be set to false in certain cases where
+		// those aren't handled correctly, most notably on Windows.
+		FileMode bool
 	}
 
 	Pack struct {
@@ -115,6 +120,7 @@ const (
 	fetchKey         = "fetch"
 	urlKey           = "url"
 	bareKey          = "bare"
+	fileModeKey      = "filemode"
 	worktreeKey      = "worktree"
 	commentCharKey   = "commentChar"
 	windowKey        = "window"
@@ -148,11 +154,31 @@ func (c *Config) Unmarshal(b []byte) error {
 	return c.unmarshalRemotes()
 }
 
+// Based off of git source code
+// https://github.com/git/git/blob/2d3b1c576c85b7f5db1f418907af00ab88e0c303/config.c#L1042-L1057
+func parseBool(opts format.Options, key string, def bool) bool {
+	v, exists := opts.GetValue(key)
+	if !exists {
+		return def
+	}
+	switch strings.ToLower(v) {
+	case "false", "no", "off":
+		return false
+	case "true", "yes", "on":
+		return true
+	}
+	i, err := strconv.Atoi(v)
+	if err != nil {
+		return def
+	}
+	return i != 0
+}
+
 func (c *Config) unmarshalCore() {
 	s := c.Raw.Section(coreSection)
-	if s.Options.Get(bareKey) == "true" {
-		c.Core.IsBare = true
-	}
+
+	c.Core.IsBare = parseBool(s.Options, bareKey, c.Core.IsBare)
+	c.Core.FileMode = parseBool(s.Options, fileModeKey, true)
 
 	c.Core.Worktree = s.Options.Get(worktreeKey)
 	c.Core.CommentChar = s.Options.Get(commentCharKey)
@@ -234,6 +260,7 @@ func (c *Config) Marshal() ([]byte, error) {
 func (c *Config) marshalCore() {
 	s := c.Raw.Section(coreSection)
 	s.SetOption(bareKey, fmt.Sprintf("%t", c.Core.IsBare))
+	s.SetOption(fileModeKey, fmt.Sprintf("%t", c.Core.FileMode))
 
 	if c.Core.Worktree != "" {
 		s.SetOption(worktreeKey, c.Core.Worktree)
diff --git a/plumbing/format/config/option.go b/plumbing/format/config/option.go
index d4775e4f0..fd1654b49 100644
--- a/plumbing/format/config/option.go
+++ b/plumbing/format/config/option.go
@@ -45,13 +45,19 @@ func (opts Options) GoString() string {
 // In order to get all possible values for the same key,
 // use GetAll.
 func (opts Options) Get(key string) string {
+	ret, _ := opts.GetValue(key)
+	return ret
+}
+
+// GetValue is similar to Get, but returns also whether the value was found.
+func (opts Options) GetValue(key string) (string, bool) {
 	for i := len(opts) - 1; i >= 0; i-- {
 		o := opts[i]
 		if o.IsKey(key) {
-			return o.Value
+			return o.Value, true
 		}
 	}
-	return ""
+	return "", false
 }
 
 // GetAll returns all possible values for the same key.
diff --git a/worktree_status.go b/worktree_status.go
index 0e113d093..6661b45ef 100644
--- a/worktree_status.go
+++ b/worktree_status.go
@@ -78,6 +78,11 @@ func (w *Worktree) status(commit plumbing.Hash) (Status, error) {
 		return nil, err
 	}
 
+	cfg, err := w.r.Config()
+	if err != nil {
+		return nil, err
+	}
+
 	for _, ch := range right {
 		a, err := ch.Action()
 		if err != nil {
@@ -479,12 +484,26 @@ func (w *Worktree) doUpdateFileToIndex(e *index.Entry, filename string, h plumbi
 		return err
 	}
 
+	isNew := e.Hash == plumbing.ZeroHash
 	e.Hash = h
 	e.ModifiedAt = info.ModTime()
-	e.Mode, err = filemode.NewFromOSFileMode(info.Mode())
+
+	cfg, err := w.r.Config()
 	if err != nil {
 		return err
 	}
+	if cfg.Core.FileMode || !info.Mode().IsRegular() {
+		e.Mode, err = filemode.NewFromOSFileMode(info.Mode())
+		if err != nil {
+			return err
+		}
+	} else if isNew {
+		// https://github.com/git/git/blob/2d3b1c576c85b7f5db1f418907af00ab88e0c303/cache.h#L276-L280
+		// If this is a new file, make it a regular file. Otherwise, e.Mode
+		// can be kept as-is. This avoids the index marking the file as modified
+		// when only the mode has changed and fileMode == false
+		e.Mode = filemode.Regular
+	}
 
 	if e.Mode.IsRegular() {
 		e.Size = uint32(info.Size())