RTF Input: Fix regression in conversion of WMF images on linux at least, maybe on other platforms as well

src/calibre/utils/magick/__init__.py

@@ -109,6 +109,13 @@ class Image(_magick.Image): # {{{
         return _magick.Image.load(self, bytes(data))
 
     def open(self, path_or_file):
+        if not hasattr(path_or_file, 'read') and \
+            path_or_file.lower().endswith('.wmf'):
+            # Special handling for WMF files as ImageMagick seems
+            # to hand while reading them from a blob on linux
+            if isinstance(path_or_file, unicode):
+                path_or_file = path_or_file.encode(filesystem_encoding)
+            return _magick.Image.read(self, path_or_file)
         data = path_or_file
         if hasattr(data, 'read'):
             data = data.read()

src/calibre/utils/magick/magick.c

@@ -414,6 +414,24 @@ magick_Image_load(magick_Image *self, PyObject *args, PyObject *kwargs) {
 
 // }}}
 
+// Image.load {{{
+static PyObject *
+magick_Image_read(magick_Image *self, PyObject *args, PyObject *kwargs) {
+    const char *data;
+    MagickBooleanType res;
+    
+    if (!PyArg_ParseTuple(args, "s", &data)) return NULL;
+
+    res = MagickReadImage(self->wand, data);
+
+    if (!res)
+        return magick_set_exception(self->wand);
+
+    Py_RETURN_NONE;
+}
+
+// }}}
+
 // Image.create_canvas {{{
 static PyObject *
 magick_Image_create_canvas(magick_Image *self, PyObject *args, PyObject *kwargs)
@@ -873,6 +891,10 @@ static PyMethodDef magick_Image_methods[] = {
      "Load an image from a byte buffer (string)"
     },
 
+    {"read", (PyCFunction)magick_Image_read, METH_VARARGS,
+     "Read image from path. Path must be a bytestring in the filesystem encoding"
+    },
+
     {"export", (PyCFunction)magick_Image_export, METH_VARARGS,
      "export(format) -> bytestring\n\n Export the image as the specified format"
     },