From 09742317fd6e85313f5616008a2f879cda0455cf Mon Sep 17 00:00:00 2001
From: Trent Mick <trentm@gmail.com>
Date: Fri, 26 Aug 2016 00:01:04 -0700
Subject: [PATCH] Ensure `log.info({err: err})` results in a "msg" value, just
 like `log.info(err)`

Fixes #426
---
 CHANGES.md    | 3 ++-
 lib/bunyan.js | 8 +++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index a08b1df..4d7c67a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -8,7 +8,8 @@ Known issues:
 
 ## 1.8.2 (not yet released)
 
-(nothing yet)
+- [issue #426] Ensure `log.info({err: err})` results in a "msg" value, just
+  like `log.info(err)`.
 
 
 ## 1.8.1
diff --git a/lib/bunyan.js b/lib/bunyan.js
index c595b2b..0817054 100644
--- a/lib/bunyan.js
+++ b/lib/bunyan.js
@@ -980,7 +980,13 @@ function mkLogEmitter(minLevel) {
                 msgArgs[0] = util.inspect(msgArgs[0]);
             } else {  // `log.<level>(fields, msg, ...)`
                 fields = args[0];
-                msgArgs = Array.prototype.slice.call(args, 1);
+                if (args.length === 1 && fields.err
+                    && fields.err instanceof Error)
+                {
+                    msgArgs = [fields.err.message];
+                } else {
+                    msgArgs = Array.prototype.slice.call(args, 1);
+                }
             }
 
             // Build up the record object.