From 7cd2929d7c3c7c4eaecf0b3f9381bb0d2c37ea54 Mon Sep 17 00:00:00 2001
From: Sorah Fukumori <her@sorah.jp>
Date: Thu, 30 Nov 2017 19:11:23 +0900
Subject: [PATCH 2/2] Add Exception#display to log exception

[Feature #14141]
---
 NEWS    |  1 +
 error.c | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/NEWS b/NEWS
index 27467d2..e4136cd 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,7 @@ with all sufficient information, see the ChangeLog file or Redmine
 * Exception
 
   * Exception#formatted  [Feature #14141]
+  * Exception#display  [Feature #14141]
 
 * Dir
 
diff --git a/error.c b/error.c
index 72e0793..c918fd6 100644
--- a/error.c
+++ b/error.c
@@ -938,6 +938,42 @@ exc_formatted(VALUE exc)
 
 /*
  * call-seq:
+ *   exception.display(port=$stderr) -> nil
+ *
+ * Prints formatted <i>exception</i> on the given port (default to <code>$stderr</code>).
+ * Format includes backtrace, exception class and exception message.
+ *
+ * This method is useful to log caught exceptions.
+ *
+ *     begin
+ *       some_work
+ *     rescue => e
+ *       e.display
+ *       retry
+ *     end
+ */
+
+static VALUE
+exc_display(int argc, VALUE *argv, VALUE exc)
+{
+    VALUE str = rb_str_new2("");
+    VALUE out;
+
+    if (argc == 0) {
+        out = rb_stderr;
+    }
+    else {
+        rb_scan_args(argc, argv, "01", &out);
+    }
+
+    rb_ec_error_write(exc, Qundef, str);
+    rb_io_write(out, str);
+
+    return Qnil;
+}
+
+/*
+ * call-seq:
  *   exception.message   ->  string
  *
  * Returns the result of invoking <code>exception.to_s</code>.
@@ -2199,6 +2235,7 @@ Init_Exception(void)
     rb_define_method(rb_eException, "==", exc_equal, 1);
     rb_define_method(rb_eException, "to_s", exc_to_s, 0);
     rb_define_method(rb_eException, "formatted", exc_formatted, 0);
+    rb_define_method(rb_eException, "display", exc_display, -1);
 
     rb_define_method(rb_eException, "message", exc_message, 0);
     rb_define_method(rb_eException, "inspect", exc_inspect, 0);
-- 
2.10.2