diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..26283617
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*.pyc
+waf
diff --git a/ChangeLog b/ChangeLog
index 497ba9ad..66382bdf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,7 @@ NEW IN WAF 1.6.9
 * Added a workaround to avoid creating include folders not under the build directory #1049
 * Added a default virtual folder structure for out-of-tree build files #1053
 * Added a way to set variants containing /, for example linux/debug
+* Added a more intuitive behaviour for conf.setenv() #1062
 
 NEW IN WAF 1.6.8
 ----------------
diff --git a/waflib/Configure.py b/waflib/Configure.py
index 92799733..eb1e4d4b 100644
--- a/waflib/Configure.py
+++ b/waflib/Configure.py
@@ -111,7 +111,8 @@ class ConfigurationContext(Context.Context):
 
 	def setenv(self, name, env=None):
 		"""
-		Set a new config set for conf.env
+		Set a new config set for conf.env. If a config set of that name already exists,
+		recall it without modification.
 
 		The name is the filename prefix to save to ``c4che/NAME_cache.py``, and it
 		is also used as *variants* by the build commands.
@@ -130,12 +131,13 @@ class ConfigurationContext(Context.Context):
 		:param env: ConfigSet to copy, or an empty ConfigSet is created
 		:type env: :py:class:`waflib.ConfigSet.ConfigSet`
 		"""
-		if not env:
-			env = ConfigSet.ConfigSet()
-			self.prepare_env(env)
-		else:
-			env = env.derive()
-		self.all_envs[name] = env
+		if name not in self.all_envs or env:
+			if not env:
+				env = ConfigSet.ConfigSet()
+				self.prepare_env(env)
+			else:
+				env = env.derive()
+			self.all_envs[name] = env
 		self.variant = name
 
 	def get_env(self):
diff --git a/waflib/Tools/fc_config.py b/waflib/Tools/fc_config.py
index 0fd06bc8..3b460349 100644
--- a/waflib/Tools/fc_config.py
+++ b/waflib/Tools/fc_config.py
@@ -441,3 +441,21 @@ def set_lib_pat(self):
 	"""Set the fortran flags for linking with the python library"""
 	self.env['fcshlib_PATTERN'] = self.env['pyext_PATTERN']
 
+@conf
+def detect_openmp(self):
+	for x in ['-fopenmp','-openmp','-mp','-xopenmp','-omp','-qsmp=omp']:
+		try:
+			conf.check_fc(
+				msg='Checking for OpenMP flag %s' % x,
+				fragment='program main\n  call omp_get_num_threads()\nend program main',
+				fcflags=x,
+				linkflags=x,
+				uselib_store='OPENMP'
+			)
+		except conf.errors.ConfigurationError:
+			pass
+		else:
+			break
+	else:
+		conf.fatal('Could not find OpenMP')
+
diff --git a/waflib/Tools/ifort.py b/waflib/Tools/ifort.py
index b999efb2..75884167 100644
--- a/waflib/Tools/ifort.py
+++ b/waflib/Tools/ifort.py
@@ -19,6 +19,14 @@ def find_ifort(conf):
 def ifort_modifier_cygwin(conf):
 	raise NotImplementedError("Ifort on cygwin not yet implemented")
 
+@conf
+def ifort_modifier_win32(conf):
+	fc_config.fortran_modifier_win32(conf)
+
+@conf
+def ifort_modifier_darwin(conf):
+	fc_config.fortran_modifier_darwin(conf)
+
 @conf
 def ifort_modifier_platform(conf):
 	dest_os = conf.env['DEST_OS'] or Utils.unversioned_sys_platform()
@@ -47,3 +55,4 @@ def configure(conf):
 	conf.find_ar()
 	conf.fc_flags()
 	conf.ifort_modifier_platform()
+