From 67465fbc57a5bbfd03c69f44555f68b14bdfbb2b Mon Sep 17 00:00:00 2001
From: Antoine Grondin <antoinegrondin@gmail.com>
Date: Thu, 1 Sep 2016 09:58:51 -0400
Subject: [PATCH] fix keep flag to keep unchanged keys

---
 handler.go        | 32 +++++++++++++++++++-------------
 json_handler.go   |  2 +-
 logrus_handler.go |  2 +-
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/handler.go b/handler.go
index bc77a8ee..ad30c01f 100644
--- a/handler.go
+++ b/handler.go
@@ -35,26 +35,32 @@ type HandlerOptions struct {
 	ValRGB         RGB
 }
 
-func (h *HandlerOptions) setup() {
-	h.Skip = make(map[string]struct{})
-	h.Keep = make(map[string]struct{})
-}
-
 func (h *HandlerOptions) shouldShowKey(key string) bool {
 	if len(h.Keep) != 0 {
-		_, keep := h.Keep[key]
-		return keep
+		if _, keep := h.Keep[key]; keep {
+			return true
+		}
 	}
 	if len(h.Skip) != 0 {
-		_, skip := h.Skip[key]
-		return !skip
+		if _, skip := h.Skip[key]; skip {
+			return false
+		}
 	}
 	return true
 }
 
+func (h *HandlerOptions) shouldShowUnchanged(key string) bool {
+	if len(h.Keep) != 0 {
+		if _, keep := h.Keep[key]; keep {
+			return true
+		}
+	}
+	return false
+}
+
 func (h *HandlerOptions) SetSkip(skip []string) {
-	if len(h.Keep) != 0 || h.Skip == nil {
-		h.setup()
+	if h.Skip == nil {
+		h.Skip = make(map[string]struct{})
 	}
 	for _, key := range skip {
 		h.Skip[key] = struct{}{}
@@ -62,8 +68,8 @@ func (h *HandlerOptions) SetSkip(skip []string) {
 }
 
 func (h *HandlerOptions) SetKeep(keep []string) {
-	if len(h.Skip) != 0 || h.Keep == nil {
-		h.setup()
+	if h.Keep == nil {
+		h.Keep = make(map[string]struct{})
 	}
 	for _, key := range keep {
 		h.Keep[key] = struct{}{}
diff --git a/json_handler.go b/json_handler.go
index 6dd2b27e..5f5f56e3 100644
--- a/json_handler.go
+++ b/json_handler.go
@@ -162,7 +162,7 @@ func (h *JSONHandler) joinKVs(skipUnchanged bool, sep string) []string {
 		}
 
 		if skipUnchanged {
-			if lastV, ok := h.last[k]; ok && lastV == v {
+			if lastV, ok := h.last[k]; ok && lastV == v && !h.Opts.shouldShowUnchanged(k) {
 				continue
 			}
 		}
diff --git a/logrus_handler.go b/logrus_handler.go
index edf824ae..c7f67cf1 100644
--- a/logrus_handler.go
+++ b/logrus_handler.go
@@ -135,7 +135,7 @@ func (h *LogrusHandler) joinKVs(skipUnchanged bool, sep string) []string {
 		}
 
 		if skipUnchanged {
-			if lastV, ok := h.last[k]; ok && lastV == v {
+			if lastV, ok := h.last[k]; ok && lastV == v && !h.Opts.shouldShowUnchanged(k) {
 				continue
 			}
 		}