From 181939c8419794f14fc0248188111b6e1673e7e0 Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Tue, 5 Apr 2016 06:35:51 +0000
Subject: [PATCH] lib/ignore: Correct case insensitive matching on Mac/Windows

There was a bug in that we only did the lowercase folding when the
pattern had an explicit (?i), which is not the case on Windows/Mac
necessarily.
---
 lib/ignore/ignore.go      |  6 +++++-
 lib/ignore/ignore_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/lib/ignore/ignore.go b/lib/ignore/ignore.go
index 12ddf4d2e..d52c130b5 100644
--- a/lib/ignore/ignore.go
+++ b/lib/ignore/ignore.go
@@ -229,8 +229,12 @@ func parseIgnoreFile(fd io.Reader, currentFile string, seen map[string]bool) ([]
 		}
 
 		if strings.HasPrefix(line, "(?i)") {
-			line = strings.ToLower(line[4:])
 			pattern.foldCase = true
+			line = line[4:]
+		}
+
+		if pattern.foldCase {
+			line = strings.ToLower(line)
 		}
 
 		var err error
diff --git a/lib/ignore/ignore_test.go b/lib/ignore/ignore_test.go
index 7d42b2dc7..6ea3d6c66 100644
--- a/lib/ignore/ignore_test.go
+++ b/lib/ignore/ignore_test.go
@@ -531,3 +531,28 @@ func TestWindowsPatterns(t *testing.T) {
 		}
 	}
 }
+
+func TestAutomaticCaseInsensitivity(t *testing.T) {
+	// We should do case insensitive matching by default on some platforms.
+	if runtime.GOOS != "windows" && runtime.GOOS != "darwin" {
+		t.Skip("Windows/Mac specific test")
+		return
+	}
+
+	stignore := `
+	A/B
+	c/d
+	`
+	pats := New(true)
+	err := pats.Parse(bytes.NewBufferString(stignore), ".stignore")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []string{`a/B`, `C/d`}
+	for _, pat := range tests {
+		if !pats.Match(pat) {
+			t.Errorf("Should match %s", pat)
+		}
+	}
+}