gpython: Support -c<command>, not only -c <command>

And same for -m<module> - becuase Python supports it this way.

Before the patch:

	$ python '-cprint "hello world"'
	hello world
	$ gpython '-cprint "hello world"'
	unknown option: '-cprint "hello world"'

After the patch:

	$ python '-cprint "hello world"'
	hello world
	$ gpython '-cprint "hello world"'
	hello world

/reviewed-on nexedi/pygolang!5

gpython/__init__.py

@@ -71,22 +71,32 @@ def pymain(argv):
         return
 
     # -c command
-    if argv[0] == '-c':
-        sys.argv = argv[0:1] + argv[2:] # python leaves '-c' as argv[0]
+    if argv[0].startswith('-c'):
+        cmd  = argv[0][2:] # -c<command> also works
+        argv = argv[1:]
+        if cmd == '':
+            cmd  = argv[0]
+            argv = argv[1:]
+        sys.argv = ['-c'] + argv # python leaves '-c' as argv[0]
         sys.path.insert(0, '')   # cwd
 
         # exec with the same globals `python -c ...` does
         g = {'__name__':    '__main__',
              '__doc__':     None,
              '__package__': None}
-        six.exec_(argv[1], g)
+        six.exec_(cmd, g)
 
     # -m module
-    elif argv[0] == '-m':
+    elif argv[0].startswith('-m'):
+        mod  = argv[0][2:] # -m<module> also works
+        argv = argv[1:]
+        if mod == '':
+            mod  = argv[0]
+            argv = argv[1:]
         # search sys.path for module and run corresponding .py file as script
-        sys.argv = argv[1:]
+        sys.argv = [mod] + argv
         sys.path.insert(0, '')  # cwd
-        runpy.run_module(sys.argv[0], init_globals={'__doc__': None},
+        runpy.run_module(mod, init_globals={'__doc__': None},
                          run_name='__main__', alter_sys=True)
 
     elif argv[0].startswith('-'):

gpython/gpython_test.py

@@ -111,15 +111,21 @@ def test_pymain():
     _ = pyout([], stdin=b'import hello\n', cwd=testdata)
     assert _ == b"hello\nworld\n['']\n"
 
-    # -c
+    # -c <command>
     _ = pyout(['-c', 'import hello', 'abc', 'def'], cwd=testdata)
     assert _ == b"hello\nworld\n['-c', 'abc', 'def']\n"
+    # -c<command> should also work
+    __ = pyout(['-cimport hello', 'abc', 'def'], cwd=testdata)
+    assert __ == _
 
-    # -m
+    # -m <module>
     _ = pyout(['-m', 'hello', 'abc', 'def'], cwd=testdata)
     # realpath rewrites e.g. `local/lib -> lib` if local/lib is symlink
     hellopy = realpath(join(testdata, 'hello.py'))
     assert _ == b"hello\nworld\n['%s', 'abc', 'def']\n" % b(hellopy)
+    # -m<module>
+    __ = pyout(['-mhello', 'abc', 'def'], cwd=testdata)
+    assert __ == _
 
     # file
     _ = pyout(['testdata/hello.py', 'abc', 'def'], cwd=here)