From: Takatsugu Nokubi <takatsugu.nokubi@robotfund.co.jp>
Date: Tue, 23 Jul 2019 17:12:43 +0900
Subject: assign default error message

---
 src/stb_image.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/stb_image.h b/src/stb_image.h
index 2673809..09ebbd5 100644
--- a/src/stb_image.h
+++ b/src/stb_image.h
@@ -845,6 +845,8 @@ static const char *stbi__g_failure_reason;
 
 STBIDEF const char *stbi_failure_reason(void)
 {
+   if (stbi__g_failure_reason == NULL)
+      stbi__g_failure_reason = "unknwon error, refer error message before assignment";
    return stbi__g_failure_reason;
 }