From a67b81140b7acf798bf8c656bfc31ff74e6ce3ed Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Fri, 16 Aug 2019 09:12:06 -0700
Subject: [PATCH] Add reraise_write_errors keyword argument to Logger and
 LogDevice

This allows the user to specify exception classes to treat as regular
exceptions instead of being swallowed.  Among other things, it is
useful for having Logger work with Timeout.

Fixes Ruby Bug 9115.
---
 lib/logger.rb              | 9 +++++++--
 lib/logger/log_device.rb   | 9 ++++++++-
 test/logger/test_logger.rb | 9 +++++++++
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/lib/logger.rb b/lib/logger.rb
index 4940999..3a09c9d 100644
--- a/lib/logger.rb
+++ b/lib/logger.rb
@@ -575,10 +575,14 @@ def fatal!; self.level = FATAL; end
   # - +shift_period_suffix+: sets the format for the filename suffix
   #   for periodic log file rotation; default is <tt>'%Y%m%d'</tt>.
   #   See {Periodic Rotation}[rdoc-ref:Logger@Periodic+Rotation].
+  # - +reraise_write_errors+: An array of exception classes, which will
+  #   be reraised if there is an error when writing to the log device.
+  #   The default is to swallow all exceptions raised.
   #
   def initialize(logdev, shift_age = 0, shift_size = 1048576, level: DEBUG,
                  progname: nil, formatter: nil, datetime_format: nil,
-                 binmode: false, shift_period_suffix: '%Y%m%d')
+                 binmode: false, shift_period_suffix: '%Y%m%d',
+                 reraise_write_errors: [])
     self.level = level
     self.progname = progname
     @default_formatter = Formatter.new
@@ -590,7 +594,8 @@ def initialize(logdev, shift_age = 0, shift_size = 1048576, level: DEBUG,
       @logdev = LogDevice.new(logdev, shift_age: shift_age,
         shift_size: shift_size,
         shift_period_suffix: shift_period_suffix,
-        binmode: binmode)
+        binmode: binmode,
+        reraise_write_errors: reraise_write_errors)
     end
   end
 
diff --git a/lib/logger/log_device.rb b/lib/logger/log_device.rb
index 84277a2..4876adf 100644
--- a/lib/logger/log_device.rb
+++ b/lib/logger/log_device.rb
@@ -11,9 +11,10 @@ class LogDevice
     attr_reader :filename
     include MonitorMixin
 
-    def initialize(log = nil, shift_age: nil, shift_size: nil, shift_period_suffix: nil, binmode: false)
+    def initialize(log = nil, shift_age: nil, shift_size: nil, shift_period_suffix: nil, binmode: false, reraise_write_errors: [])
       @dev = @filename = @shift_age = @shift_size = @shift_period_suffix = nil
       @binmode = binmode
+      @reraise_write_errors = reraise_write_errors
       mon_initialize
       set_dev(log)
       if @filename
@@ -34,16 +35,22 @@ def write(message)
           if @shift_age and @dev.respond_to?(:stat)
             begin
               check_shift_log
+            rescue *@reraise_write_errors
+              raise
             rescue
               warn("log shifting failed. #{$!}")
             end
           end
           begin
             @dev.write(message)
+          rescue *@reraise_write_errors
+            raise
           rescue
             warn("log writing failed. #{$!}")
           end
         end
+      rescue *@reraise_write_errors
+        raise
       rescue Exception => ignored
         warn("log writing failed. #{ignored}")
       end
diff --git a/test/logger/test_logger.rb b/test/logger/test_logger.rb
index 37d0f58..2023553 100644
--- a/test/logger/test_logger.rb
+++ b/test/logger/test_logger.rb
@@ -113,6 +113,15 @@ def test_string_level
     assert_raise(ArgumentError) { @logger.level = 'something_wrong' }
   end
 
+  def test_reraise_write_errors
+    c = Object.new
+    e = Class.new(StandardError)
+    c.define_singleton_method(:write){|*| raise e}
+    c.define_singleton_method(:close){}
+    logger = Logger.new(c, :reraise_write_errors=>[e])
+    assert_raise(e) { logger.warn('foo') }
+  end
+
   def test_progname
     assert_nil(@logger.progname)
     @logger.progname = "name"