gistfile1.diff

diff --git a/client.mk b/client.mk
index de4de4c..726653b 100644
--- a/client.mk
+++ b/client.mk
@@ -78,7 +78,6 @@ ifdef CONFIG_GUESS_SCRIPT
   CONFIG_GUESS := $(shell $(CONFIG_GUESS_SCRIPT))
 endif
 
-
 ####################################
 # Sanity checks
 
@@ -89,6 +88,16 @@ $(error This source tree appears to have Windows-style line endings. To \
 convert it to Unix-style line endings, run \
 "python mozilla/build/win32/mozilla-dos2unix.py")
 endif
+
+# On windows, if $PYTHON is set in the environment, we need to make
+# sure that it's quoted -- if it's a windows-style path
+# (e.g. 'C:\Python27\python'), using $(PYTHON) as-is will cause the
+# backslashes to not get treated as path separators.
+  PYTHON := $(subst \\,/,$(PYTHON))
+  PYTHON := $(subst \,/,$(PYTHON))
+
+  TOPSRCDIR := $(subst \\,/,$(TOPSRCDIR))
+  TOPSRCDIR := $(subst \,/,$(TOPSRCDIR))
 endif
 
 ####################################
@@ -118,6 +127,10 @@ ifeq (,$(findstring -j,$(MOZ_MAKE_FLAGS)))
   MOZ_MAKE_FLAGS += -j$(cores)
 endif
 
+ifndef MOZ_OBJDIR
+  # Pull it in from environment
+  MOZ_OBJDIR ?=
+endif
 
 ifndef MOZ_OBJDIR
   MOZ_OBJDIR = obj-$(CONFIG_GUESS)
@@ -127,6 +140,11 @@ else
   ifeq (1_a,$(.PYMAKE)_$(firstword a$(subst /, ,$(MOZ_OBJDIR))))
   $(error For Windows Pymake builds, MOZ_OBJDIR must be a Windows [and not MSYS] style path.)
   endif
+
+  # Then replace any forward slashes with slashes; first
+  # doing double-forward-slashes in case of overzealous quoting
+  MOZ_OBJDIR := $(subst \\,/,$(MOZ_OBJDIR))
+  MOZ_OBJDIR := $(subst \,/,$(MOZ_OBJDIR))
   endif
 endif
 
diff --git a/config/writemozinfo.py b/config/writemozinfo.py
index abe9457..3ba19f6 100755
--- a/config/writemozinfo.py
+++ b/config/writemozinfo.py
@@ -35,6 +35,9 @@ def build_dict(env=os.environ):
     if 'TOPSRCDIR' in env:
         d["topsrcdir"] = env["TOPSRCDIR"]
 
+    if 'MOZ_OBJDIR' in env:
+        d["topobjdir"] = env["MOZ_OBJDIR"]
+
     # os
     o = env["OS_TARGET"]
     known_os = {"Linux": "linux",
diff --git a/mach b/mach
index 9aba282..635c7d4 100755
--- a/mach
+++ b/mach
@@ -20,6 +20,13 @@ def load_mach(topsrcdir):
     import mach_bootstrap
     return mach_bootstrap.bootstrap(topsrcdir)
 
+def try_run_mach(dir_path):
+    mach_path = os.path.join(dir_path, "build/mach_bootstrap.py")
+    if os.path.isfile(mach_path):
+        mach = load_mach(dir_path)
+        sys.exit(mach.run(sys.argv[1:]))
+    return False
+
 # Check whether the current directory is within a mach src or obj dir.
 for dir_path in ancestors(os.getcwd()):
     # If we find a "mozinfo.json" file, we are in the objdir.
@@ -37,15 +44,28 @@ for dir_path in ancestors(os.getcwd()):
             # 2.7.2 and earlier on Windows.
             os.environ[b"MOZCONFIG"] = str(info["mozconfig"])
 
+        if "topobjdir" in info and "MOZ_OBJDIR" not in os.environ:
+            os.environ[b"MOZ_OBJDIR"] = str(info["topobjdir"])
+
         if "topsrcdir" in info:
             # Continue searching for mach_bootstrap in the source directory.
             dir_path = info["topsrcdir"]
 
     # If we find the mach bootstrap module, we are in the srcdir.
-    mach_path = os.path.join(dir_path, "build/mach_bootstrap.py")
-    if os.path.isfile(mach_path):
-        mach = load_mach(dir_path)
-        sys.exit(mach.run(sys.argv[1:]))
+    try_run_mach(dir_path)
+
+# Then check if we have an explicit path, e.g.
+#    ../gecko/mach
+# then use cwd as the objdir and the dirname as the srcdir
+dir_path = os.path.dirname(sys.argv[0])
+if dir_path:
+    dir_path = os.path.abspath(dir_path)
+    if dir_path == os.getcwd():
+        print("implicit objdir must not be the same as the source directory!")
+        sys.exit(1)
+    print("USing implicit objdir: '%s'" % os.getcwd())
+    os.environ[b"MOZ_OBJDIR"] = str(os.getcwd())
+    try_run_mach(dir_path)
 
 print("Could not run mach: No mach source directory found")
 sys.exit(1)
diff --git a/python/mozbuild/mozbuild/base.py b/python/mozbuild/mozbuild/base.py
index e9df738..82d9bb6 100644
--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -57,7 +57,7 @@ class MozbuildObject(ProcessExecutionMixin):
     @property
     def topobjdir(self):
         if self._topobjdir is None:
-            topobj = self.mozconfig['topobjdir'] or 'obj-@CONFIG_GUESS@'
+            topobj = self.mozconfig['topobjdir'] or os.getenv('MOZ_OBJDIR') or 'obj-@CONFIG_GUESS@'
             self._topobjdir = topobj.replace("@CONFIG_GUESS@",
                                              self._config_guess)
         return self._topobjdir