plumbing: gitignore, Allow gitconfig to contain a gitignore relative to any user home. Fixes #578

Signed-off-by: Arieh Schneier <15041913+AriehSchneier@users.noreply.github.com>

2 files changed, 57 insertions, 11 deletions

diff --git a/plumbing/format/gitignore/dir.go b/plumbing/format/gitignore/dir.go
index bf6a1c1..3c4469a 100644
--- a/plumbing/format/gitignore/dir.go
+++ b/plumbing/format/gitignore/dir.go
@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"io"
 	"os"
+	"os/user"
 	"strings"
 
 	"github.com/go-git/go-billy/v5"
@@ -27,9 +28,18 @@ const (
 func readIgnoreFile(fs billy.Filesystem, path []string, ignoreFile string) (ps []Pattern, err error) {
 
 	if strings.HasPrefix(ignoreFile, "~") {
-		home, err := os.UserHomeDir()
-		if err == nil {
-			ignoreFile = strings.Replace(ignoreFile, "~", home, 1)
+		firstSlash := strings.Index(ignoreFile, "/")
+		if firstSlash == 1 {
+			home, err := os.UserHomeDir()
+			if err == nil {
+				ignoreFile = strings.Replace(ignoreFile, "~", home, 1)
+			}
+		} else if firstSlash > 1 {
+			username := ignoreFile[1:firstSlash]
+			userAccount, err := user.Lookup(username)
+			if err == nil {
+				ignoreFile = strings.Replace(ignoreFile, ignoreFile[:firstSlash], userAccount.HomeDir, 1)
+			}
 		}
 	}
 
diff --git a/plumbing/format/gitignore/dir_test.go b/plumbing/format/gitignore/dir_test.go
index 4bbba68..465c571 100644
--- a/plumbing/format/gitignore/dir_test.go
+++ b/plumbing/format/gitignore/dir_test.go
@@ -2,7 +2,9 @@ package gitignore
 
 import (
 	"os"
+	"os/user"
 	"strconv"
+	"strings"
 
 	"github.com/go-git/go-billy/v5"
 	"github.com/go-git/go-billy/v5/memfs"
@@ -12,7 +14,8 @@ import (
 type MatcherSuite struct {
 	GFS  billy.Filesystem // git repository root
 	RFS  billy.Filesystem // root that contains user home
-	RFSR billy.Filesystem // root that contains user home, but with with relative ~/.gitignore_global
+	RFSR billy.Filesystem // root that contains user home, but with relative ~/.gitignore_global
+	RFSU billy.Filesystem // root that contains user home, but with relative ~user/.gitignore_global
 	MCFS billy.Filesystem // root that contains user home, but missing ~/.gitconfig
 	MEFS billy.Filesystem // root that contains user home, but missing excludesfile entry
 	MIFS billy.Filesystem // root that contains user home, but missing .gitignore
@@ -144,6 +147,37 @@ func (s *MatcherSuite) SetUpTest(c *C) {
 
 	s.RFSR = fs
 
+	// root that contains user home, but with relative ~user/.gitignore_global
+	fs = memfs.New()
+	err = fs.MkdirAll(home, os.ModePerm)
+	c.Assert(err, IsNil)
+
+	f, err = fs.Create(fs.Join(home, gitconfigFile))
+	c.Assert(err, IsNil)
+	_, err = f.Write([]byte("[core]\n"))
+	c.Assert(err, IsNil)
+	currentUser, err := user.Current()
+	c.Assert(err, IsNil)
+	// remove domain for windows
+	username := currentUser.Username[strings.Index(currentUser.Username, "\\")+1:]
+	_, err = f.Write([]byte("	excludesfile = ~" + username + "/.gitignore_global" + "\n"))
+	c.Assert(err, IsNil)
+	err = f.Close()
+	c.Assert(err, IsNil)
+
+	f, err = fs.Create(fs.Join(home, ".gitignore_global"))
+	c.Assert(err, IsNil)
+	_, err = f.Write([]byte("# IntelliJ\n"))
+	c.Assert(err, IsNil)
+	_, err = f.Write([]byte(".idea/\n"))
+	c.Assert(err, IsNil)
+	_, err = f.Write([]byte("*.iml\n"))
+	c.Assert(err, IsNil)
+	err = f.Close()
+	c.Assert(err, IsNil)
+
+	s.RFSU = fs
+
 	// root that contains user home, but missing ~/.gitconfig
 	fs = memfs.New()
 	err = fs.MkdirAll(home, os.ModePerm)
@@ -255,14 +289,16 @@ func (s *MatcherSuite) TestDir_ReadPatterns(c *C) {
 }
 
 func (s *MatcherSuite) TestDir_ReadRelativeGlobalGitIgnore(c *C) {
-	ps, err := LoadGlobalPatterns(s.RFSR)
-	c.Assert(err, IsNil)
-	c.Assert(ps, HasLen, 2)
+	for _, fs := range []billy.Filesystem{s.RFSR, s.RFSU} {
+		ps, err := LoadGlobalPatterns(fs)
+		c.Assert(err, IsNil)
+		c.Assert(ps, HasLen, 2)
 
-	m := NewMatcher(ps)
-	c.Assert(m.Match([]string{".idea/"}, true), Equals, false)
-	c.Assert(m.Match([]string{"*.iml"}, true), Equals, true)
-	c.Assert(m.Match([]string{"IntelliJ"}, true), Equals, false)
+		m := NewMatcher(ps)
+		c.Assert(m.Match([]string{".idea/"}, true), Equals, false)
+		c.Assert(m.Match([]string{"*.iml"}, true), Equals, true)
+		c.Assert(m.Match([]string{"IntelliJ"}, true), Equals, false)
+	}
 }
 
 func (s *MatcherSuite) TestDir_LoadGlobalPatterns(c *C) {