Don't run the :before_fork hook if we're not actually going to fork.

Author: kjwierenga

lib/resque/worker.rb

@@ -136,10 +136,9 @@ def work(interval = 5.0, &block)
         if not paused? and job = reserve
           log "got: #{job.inspect}"
           job.worker = self
-          run_hook :before_fork, job
           working_on job
 
-          if @child = fork
+          if @child = fork(job)
             srand # Reseeding
             procline "Forked #{@child} at #{Time.now.to_i}"
             begin
@@ -228,8 +227,12 @@ def queues
 
     # Not every platform supports fork. Here we do our magic to
     # determine if yours does.
-    def fork
+    def fork(job)
       return if @cant_fork
+      
+      # Only run before_fork hooks if we're actually going to fork
+      # (after checking @cant_fork)
+      run_hook :before_fork, job
 
       begin
         # IronRuby doesn't support `Kernel.fork` yet

test/worker_test.rb

@@ -376,6 +376,19 @@ def self.perform
     workerA.work(0)
     assert $BEFORE_FORK_CALLED
   end
+  
+  test "Will not call a before_fork hook when the worker can't fork" do
+    Resque.redis.flushall
+    $BEFORE_FORK_CALLED = false
+    Resque.before_fork = Proc.new { $BEFORE_FORK_CALLED = true }
+    workerA = Resque::Worker.new(:jobs)
+    workerA.cant_fork = true
+
+    assert !$BEFORE_FORK_CALLED, "before_fork should not have been called before job runs"
+    Resque::Job.create(:jobs, SomeJob, 20, '/tmp')
+    workerA.work(0)
+    assert !$BEFORE_FORK_CALLED, "before_fork should not have been called after job runs"
+  end
 
   test "very verbose works in the afternoon" do
     begin