From 7c12464e7fa6f604220df2c0390109524b02aa88 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?lucaxli=28=E9=BB=8E=E5=BE=8B=29?= <lucaxli@tencent.com>
Date: Mon, 20 Jul 2020 11:32:29 +0800
Subject: [PATCH] fix set flags panic

---
 go.mod           |  3 +++
 load.go          | 16 ++++++++++++++--
 parser/parser.go |  6 ++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 go.mod

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..bca6bdb
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/spacemonkeygo/flagfile
+
+go 1.14
diff --git a/load.go b/load.go
index 49d354a..ab2abd7 100644
--- a/load.go
+++ b/load.go
@@ -49,6 +49,14 @@ func mustSet(flag_name, flag_value string) {
 	}
 }
 
+func trySet(flag_name, flag_value string) error {
+	err := flag.Set(flag_name, flag_value)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 type Option struct {
 	flagfilePath   string
 	skipArgs       bool
@@ -169,8 +177,12 @@ func Load(opts ...Option) {
 			if ignoreUnknowns && flag.Lookup(name) == nil {
 				return
 			}
-			mustSet(name, value)
-			set_flags[name] = true
+
+			err := trySet(name, value)
+
+			if err != nil {
+				set_flags[name] = true
+			}
 		})
 		fh.Close()
 		if err != nil {
diff --git a/parser/parser.go b/parser/parser.go
index 649a5f8..c5f3d32 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -70,7 +70,13 @@ func Parse(in io.Reader, cb func(key, value string)) error {
 		if len(parts) != 2 {
 			return fmt.Errorf("unable to parse flagfile line %d", lineno)
 		}
+
 		name := strings.TrimSpace(parts[0])
+		// support format like --flag=xx
+		if len(name) > 2 && name[0:2] == "--" {
+			name = name[2:]
+		}
+
 		if section != "" {
 			name = section + name
 		}