Revert misguided attempt at fixing incompatibility between -m and -i switches (better fix coming soon)

Doc/library/runpy.rst

@@ -52,11 +52,9 @@ The :mod:`runpy` module provides a single function:
 
    If the argument *alter_sys* is supplied and evaluates to ``True``, then
    ``sys.argv[0]`` is updated with the value of ``__file__`` and
-   ``sys.modules[__name__]`` is updated with a new module object for the module
-   being executed. Note that neither ``sys.argv[0]`` nor ``sys.modules[__name__]``
-   are restored to their original values before the function returns - if client
-   code needs these values preserved, it must either save them explicitly or else
-   avoid enabling the automatic alterations to :mod:`sys`.
+   ``sys.modules[__name__]`` is updated with a temporary module object for the
+   module being executed. Both ``sys.argv[0]`` and ``sys.modules[__name__]``
+   are restored to their original values before the function returns.
 
    Note that this manipulation of :mod:`sys` is not thread-safe. Other threads may
    see the partially initialised module, as well as the altered list of arguments.

Lib/runpy.py

@@ -38,15 +38,30 @@ def _run_module_code(code, init_globals=None,
     """Helper for run_module"""
     # Set up the top level namespace dictionary
     if alter_sys:
-        # Modify sys.argv[0] and sys.modules[mod_name]
+        # Modify sys.argv[0] and sys.module[mod_name]
+        temp_module = imp.new_module(mod_name)
+        mod_globals = temp_module.__dict__
+        saved_argv0 = sys.argv[0]
+        restore_module = mod_name in sys.modules
+        if restore_module:
+            saved_module = sys.modules[mod_name]
         sys.argv[0] = mod_fname
-        module = imp.new_module(mod_name)
-        sys.modules[mod_name] = module
-        mod_globals = module.__dict__
+        sys.modules[mod_name] = temp_module
+        try:
+            _run_code(code, mod_globals, init_globals,
+                      mod_name, mod_fname, mod_loader)
+        finally:
+            sys.argv[0] = saved_argv0
+        if restore_module:
+            sys.modules[mod_name] = saved_module
+        else:
+            del sys.modules[mod_name]
+        # Copy the globals of the temporary module, as they
+        # may be cleared when the temporary module goes away
+        return mod_globals.copy()
     else:
         # Leave the sys module alone
-        mod_globals = {}
-    return _run_code(code, mod_globals, init_globals,
+        return _run_code(code, {}, init_globals,
                          mod_name, mod_fname, mod_loader)
 
 

Lib/test/test_runpy.py

@@ -26,7 +26,8 @@ class RunModuleCodeTest(unittest.TestCase):
         "   module_in_sys_modules = globals() is sys.modules[__name__].__dict__\n"
         "# Check nested operation\n"
         "import runpy\n"
-        "nested = runpy._run_module_code('x=1\\n', mod_name='<run>')\n"
+        "nested = runpy._run_module_code('x=1\\n', mod_name='<run>',\n"
+        "                                          alter_sys=True)\n"
     )
 
 
@@ -37,44 +38,35 @@ class RunModuleCodeTest(unittest.TestCase):
         loader = "Now you're just being silly"
         d1 = dict(initial=initial)
         saved_argv0 = sys.argv[0]
-        try:
         d2 = _run_module_code(self.test_source,
                               d1,
                               name,
                               file,
                               loader,
-                                alter_sys=True)
+                              True)
         self.failUnless("result" not in d1)
         self.failUnless(d2["initial"] is initial)
         self.failUnless(d2["result"] == self.expected_result)
         self.failUnless(d2["nested"]["x"] == 1)
-            self.failUnless(d2["nested"]["__name__"] == "<run>")
         self.failUnless(d2["__name__"] is name)
-            self.failUnless(d2["__file__"] is file)
-            self.failUnless(d2["__loader__"] is loader)
-            self.failUnless(d2["run_argv0"] is file)
         self.failUnless(d2["run_name_in_sys_modules"])
         self.failUnless(d2["module_in_sys_modules"])
-            self.failUnless(sys.argv[0] is not saved_argv0)
-            self.failUnless(name in sys.modules)
-        finally:
-            sys.argv[0] = saved_argv0
-            if name in sys.modules:
-                del sys.modules[name]
+        self.failUnless(d2["__file__"] is file)
+        self.failUnless(d2["run_argv0"] is file)
+        self.failUnless(d2["__loader__"] is loader)
+        self.failUnless(sys.argv[0] is saved_argv0)
+        self.failUnless(name not in sys.modules)
 
     def test_run_module_code_defaults(self):
         saved_argv0 = sys.argv[0]
         d = _run_module_code(self.test_source)
         self.failUnless(d["result"] == self.expected_result)
-        self.failUnless(d["nested"]["x"] == 1)
-        self.failUnless(d["nested"]["__name__"] == "<run>")
         self.failUnless(d["__name__"] is None)
         self.failUnless(d["__file__"] is None)
         self.failUnless(d["__loader__"] is None)
         self.failUnless(d["run_argv0"] is saved_argv0)
-        self.failUnless(not d["run_name_in_sys_modules"])
+        self.failUnless("run_name" not in d)
         self.failUnless(sys.argv[0] is saved_argv0)
-        self.failUnless(None not in sys.modules)
 
 class RunModuleTest(unittest.TestCase):
 

Python/compile.c

@@ -1616,10 +1616,14 @@ compiler_while(struct compiler *c, stmt_ty s)
 		orelse = NULL;
 
 	ADDOP_JREL(c, SETUP_LOOP, end);
-	compiler_use_next_block(c, loop);
 	if (!compiler_push_fblock(c, LOOP, loop))
 		return 0;
+	compiler_use_next_block(c, loop);
 	if (constant == -1) {
+		/* XXX(ncoghlan): SF bug #1750076
+		   Use same special casing as is used in for loops
+		   A test case for this would be nice... */
+		c->u->u_lineno_set = false;
 		VISIT(c, expr, s->v.While.test);
 		ADDOP_JREL(c, JUMP_IF_FALSE, anchor);
 		ADDOP(c, POP_TOP);
@@ -3521,7 +3525,8 @@ assemble_lnotab(struct assembler *a, struct instr *i)
 	/* XXX(nnorwitz): is there a better way to handle this?
 	   for loops are special, we want to be able to trace them
 	   each time around, so we need to set an extra line number. */
-	if (d_lineno == 0 && i->i_opcode != FOR_ITER)
+	/* XXX(ncoghlan): while loops need this too */
+	if (d_lineno == 0)
 		return 1;
 
 	if (d_bytecode > 255) {