From b0bce0b8ce807e4d92a8a01fa0235727d709c21d Mon Sep 17 00:00:00 2001
From: Blake Mesdag <blakemesdag@gmail.com>
Date: Tue, 12 Apr 2016 12:07:56 -0400
Subject: Handle max_time edge cases for epoch times and add test

---
 activesupport/lib/active_support/file_update_checker.rb | 15 ++++++++++++---
 activesupport/test/file_update_checker_shared_tests.rb  | 17 +++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/activesupport/lib/active_support/file_update_checker.rb b/activesupport/lib/active_support/file_update_checker.rb
index 4f0a2dedc5..d1eb410c85 100644
--- a/activesupport/lib/active_support/file_update_checker.rb
+++ b/activesupport/lib/active_support/file_update_checker.rb
@@ -111,13 +111,22 @@ module ActiveSupport
     # healthy to consider this edge case because with mtimes in the future
     # reloading is not triggered.
     def max_mtime(paths)
+      return nil if paths.empty?
+
       time_now = Time.now
-      time_at_zero = Time.at(0)
-      max_time = time_at_zero
+      max_time = nil
 
       paths.each do |path|
         time = File.mtime(path)
 
+        if max_time.nil?
+          if time.compare_without_coercion(time_now) < 0
+            max_time = time
+          end
+
+          next
+        end
+
         # This avoids ActiveSupport::CoreExt::Time#time_with_coercion
         # which is super slow when comparing two Time objects
         #
@@ -128,7 +137,7 @@ module ActiveSupport
         end
       end
 
-      max_time.object_id == time_at_zero.object_id ? nil : max_time
+      max_time
     end
 
     def compile_glob(hash)
diff --git a/activesupport/test/file_update_checker_shared_tests.rb b/activesupport/test/file_update_checker_shared_tests.rb
index 5207860a0e..a78c3a67b6 100644
--- a/activesupport/test/file_update_checker_shared_tests.rb
+++ b/activesupport/test/file_update_checker_shared_tests.rb
@@ -134,6 +134,23 @@ module FileUpdateCheckerSharedTests
     assert_equal 1, i
   end
 
+  test 'should return max_time for files with mtime = Time.at(0)' do
+    i = 0
+
+    FileUtils.touch(tmpfiles)
+
+    now  = Time.now
+    time = Time.at(0) # wrong mtime from the future
+    File.utime(time, time, tmpfiles[0])
+
+    checker = new_checker(tmpfiles) { i += 1 }
+
+    touch(tmpfiles[1..-1])
+
+    assert checker.execute_if_updated
+    assert_equal 1, i
+  end
+
   test 'should cache updated result until execute' do
     i = 0
 
-- 
cgit v1.2.3


From fad2428e357f5e88e745aa402e21cdfcb700fbc0 Mon Sep 17 00:00:00 2001
From: Blake Mesdag <blakemesdag@gmail.com>
Date: Tue, 12 Apr 2016 13:29:56 -0400
Subject: More readable version

---
 .../lib/active_support/file_update_checker.rb      | 23 ++++++++++------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/activesupport/lib/active_support/file_update_checker.rb b/activesupport/lib/active_support/file_update_checker.rb
index d1eb410c85..2a1a8f9797 100644
--- a/activesupport/lib/active_support/file_update_checker.rb
+++ b/activesupport/lib/active_support/file_update_checker.rb
@@ -114,30 +114,27 @@ module ActiveSupport
       return nil if paths.empty?
 
       time_now = Time.now
-      max_time = nil
+      max_mtime = nil
 
       paths.each do |path|
-        time = File.mtime(path)
+        mtime = File.mtime(path)
 
-        if max_time.nil?
-          if time.compare_without_coercion(time_now) < 0
-            max_time = time
-          end
-
-          next
-        end
+        # Prevent dates in the future being considered
+        # Equivalent ruby:
+        # time.now < mtime
+        next if time_now.compare_without_coercion(mtime) < 0
 
         # This avoids ActiveSupport::CoreExt::Time#time_with_coercion
         # which is super slow when comparing two Time objects
         #
         # Equivalent Ruby:
-        # time < time_now && time > max_time
-        if time.compare_without_coercion(time_now) < 0 && time.compare_without_coercion(max_time) > 0
-          max_time = time
+        # max_mtime.nil? || max_mtime < mtime
+        if max_mtime.nil? || max_mtime.compare_without_coercion(mtime) < 0
+          max_mtime = mtime
         end
       end
 
-      max_time
+      max_mtime
     end
 
     def compile_glob(hash)
-- 
cgit v1.2.3


From f05704fc1aec5f859c78a75d26dc694c51a729af Mon Sep 17 00:00:00 2001
From: Blake Mesdag <blakemesdag@gmail.com>
Date: Tue, 12 Apr 2016 13:49:41 -0400
Subject: No more need for an early return

---
 activesupport/lib/active_support/file_update_checker.rb | 2 --
 1 file changed, 2 deletions(-)

diff --git a/activesupport/lib/active_support/file_update_checker.rb b/activesupport/lib/active_support/file_update_checker.rb
index 2a1a8f9797..fa0b1a4bcf 100644
--- a/activesupport/lib/active_support/file_update_checker.rb
+++ b/activesupport/lib/active_support/file_update_checker.rb
@@ -111,8 +111,6 @@ module ActiveSupport
     # healthy to consider this edge case because with mtimes in the future
     # reloading is not triggered.
     def max_mtime(paths)
-      return nil if paths.empty?
-
       time_now = Time.now
       max_mtime = nil
 
-- 
cgit v1.2.3