setup.py: add extra error messages.

SVGSurface: Change from bytes-mode to text-mode, so SVG files can be written
to sys.stdout. Fixes bug #50989.

4 files changed, 68 insertions, 36 deletions

diff --git a/doc/reference/surfaces.rst b/doc/reference/surfaces.rst
index 0ba51c9..949b05e 100644
--- a/doc/reference/surfaces.rst
+++ b/doc/reference/surfaces.rst
@@ -227,7 +227,7 @@ class Surface()
    .. method:: write_to_png(fobj)
 
       :param fobj: the file to write to
-      :type fobj: str, file or file-like object
+      :type fobj: filename (str), file or a file-like bytes-mode object
       :raises: *MemoryError* if memory could not be allocated for the operation
 
                *IOError* if an I/O error occurs while attempting to write the file
@@ -341,7 +341,7 @@ multi-page vector surface backend.
 .. class:: PDFSurface(fobj, width_in_points, height_in_points)
 
    :param fobj: a filename or writable file object. None may be used to specify no output. This will generate a *PDFSurface* that may be queried and used as a source, without generating a temporary file.
-   :type fobj: None, str, file or file-like object
+   :type fobj: None, filename (str), file or a file-like bytes-mode object
    :param width_in_points: width of the surface, in points
      (1 point == 1/72.0 inch)
    :type  width_in_points: float
@@ -383,7 +383,7 @@ is a multi-page vector surface backend.
 .. class:: PSSurface(fobj, width_in_points, height_in_points)
 
    :param fobj: a filename or writable file object. None may be used to specify no output. This will generate a *PSSurface* that may be queried and used as a source, without generating a temporary file.
-   :type fobj: None, str, file or file-like object
+   :type fobj: None, filename (str), file or a file-like bytes-mode object
    :param width_in_points: width of the surface, in points
      (1 point == 1/72.0 inch)
    :type  width_in_points: float
@@ -646,8 +646,10 @@ multi-page vector surface backend
 
 .. class:: SVGSurface(fobj, width_in_points, height_in_points)
 
-   :param fobj: a filename or writable file object. None may be used to specify no output. This will generate a *SVGSurface* that may be queried and used as a source, without generating a temporary file.
-   :type fobj: None, str, file or file-like object
+   :param fobj: a filename or writable file object. None may be used to
+   specify no output. This will generate a *SVGSurface* that may be queried
+   and used as a source, without generating a temporary file.
+   :type fobj: None, filename (str), file or a file-like text-mode object
    :param width_in_points: width of the surface, in points (1 point == 1/72.0 inch)
    :type  width_in_points: float
    :param height_in_points: height of the surface, in points (1 point == 1/72.0 inch)
@@ -735,13 +737,14 @@ extension if it is available.
    :param width: The width of the surface
    :param height: The height of the surface
 
-   Informs cairo of the new size of the X Drawable underlying the surface. For a surface created
-   for a Window (rather than a Pixmap), this function must be called each time the size of the
-   window changes. (For a subwindow, you are normally resizing the window yourself, but for a
-   toplevel window, it is necessary to listen for ConfigureNotify events.)
+   Informs cairo of the new size of the X Drawable underlying the surface. For
+   a surface created for a Window (rather than a Pixmap), this function must
+   be called each time the size of the window changes. (For a subwindow, you
+   are normally resizing the window yourself, but for a toplevel window, it is
+   necessary to listen for ConfigureNotify events.)
 
-   A Pixmap can never change size, so it is never necessary to call this function on a surface
-   created for a Pixmap.
+   A Pixmap can never change size, so it is never necessary to call this
+   function on a surface created for a Pixmap.
 
 
 class XlibSurface(:class:`Surface`)
diff --git a/setup.py b/setup.py
index 808e34a..a93a650 100755
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,12 @@ def pkg_config_version_check(pkg, version):
     raise SystemExit(pipe.stderr.read().decode())
 
 def pkg_config_parse(opt, pkg):
+  check = "pkg-config %s %s" % (opt, pkg)
   pipe = call("pkg-config %s %s" % (opt, pkg))
+  if pipe.returncode != 0:
+    print(check, ' Failed')
+    raise SystemExit(pipe.stderr.read().decode())
+
   output = pipe.stdout.read()
   output = output.decode() # get the str
   opt = opt[-2:]
diff --git a/src/surface.c b/src/surface.c
index d98c498..4701a4b 100644
--- a/src/surface.c
+++ b/src/surface.c
@@ -121,10 +121,10 @@ PycairoSurface_FromSurface (cairo_surface_t *surface, PyObject *base) {
 
 /* for use with
  * cairo_surface_write_to_png_stream()
- * cairo_pdf/ps/svg_surface_create_for_stream()
+ * cairo_pdf/ps_surface_create_for_stream()
  */
 static cairo_status_t
-_write_func (void *closure, const unsigned char *data, unsigned int length) {
+_write_bytes_func (void *closure, const unsigned char *data, unsigned int length) {
   PyGILState_STATE gstate = PyGILState_Ensure();
   PyObject *res = PyObject_CallMethod ((PyObject *)closure, "write", "(y#)",
 				       data, (Py_ssize_t)length);
@@ -140,6 +140,26 @@ _write_func (void *closure, const unsigned char *data, unsigned int length) {
   return CAIRO_STATUS_SUCCESS;
 }
 
+/* for use with
+ * cairo_svg_surface_create_for_stream()
+ */
+static cairo_status_t
+_write_str_func (void *closure, const unsigned char *data, unsigned int length) {
+  PyGILState_STATE gstate = PyGILState_Ensure();
+  PyObject *res = PyObject_CallMethod ((PyObject *)closure, "write", "(s#)",
+				       data, (Py_ssize_t)length);
+  if (res == NULL) {
+    /* an exception has occurred, it will be picked up later by
+     * Pycairo_Check_Status()
+     */
+    PyGILState_Release(gstate);
+    return CAIRO_STATUS_WRITE_ERROR;
+  }
+  Py_DECREF(res);
+  PyGILState_Release(gstate);
+  return CAIRO_STATUS_SUCCESS;
+}
+
 static void
 surface_dealloc (PycairoSurface *o) {
   if (o->surface) {
@@ -307,12 +327,12 @@ surface_write_to_png (PycairoSurface *o, PyObject *args) {
       Py_XDECREF(writer);
       PyErr_SetString(PyExc_TypeError,
 "Surface.write_to_png takes one argument which must be a filename (str), file "
-"object, or a file-like object which has a \"write\" method (like StringIO)");
+"object, or a file-like bytes-mode object which has a \"write\" method");
       return NULL;
     }
     Py_DECREF(writer);
     Py_BEGIN_ALLOW_THREADS;
-    status = cairo_surface_write_to_png_stream (o->surface, _write_func,
+    status = cairo_surface_write_to_png_stream (o->surface, _write_bytes_func,
 						file);
     Py_END_ALLOW_THREADS;
   }
@@ -462,7 +482,7 @@ image_surface_create_for_data (PyTypeObject *type, PyObject *args) {
 
 #ifdef CAIRO_HAS_PNG_FUNCTIONS
 static cairo_status_t
-_read_func (void *closure, unsigned char *data, unsigned int length) {
+_read_bytes_func (void *closure, unsigned char *data, unsigned int length) {
   char *buffer;
   Py_ssize_t str_length;
   cairo_status_t status = CAIRO_STATUS_READ_ERROR;
@@ -518,13 +538,13 @@ image_surface_create_from_png (PyTypeObject *type, PyObject *args) {
     Py_XDECREF(reader);
     PyErr_SetString(PyExc_TypeError,
 "ImageSurface.create_from_png argument must be a filename (str), file object, "
-"or an object that has a \"read\" method (like StringIO)");
+"or a file-like bytes-mode object which has a \"read\" method");
     return NULL;
   }
   Py_DECREF(reader);
 
   Py_BEGIN_ALLOW_THREADS;
-  is = cairo_image_surface_create_from_png_stream (_read_func, file);
+  is = cairo_image_surface_create_from_png_stream (_read_bytes_func, file);
   Py_END_ALLOW_THREADS;
   return PycairoSurface_FromSurface (is, NULL);
 }
@@ -708,14 +728,14 @@ pdf_surface_new (PyTypeObject *type, PyObject *args, PyObject *kwds) {
 "  None, or\n"
 "  a filename (str), or\n"
 "  a file object, or\n"
-"  an object that has a \"write\" method (like StringIO)."
+"  a file-like bytes-mode object which has a \"write\" method."
 		    );
     return NULL;
   }
   Py_DECREF(writer);
 
   Py_BEGIN_ALLOW_THREADS;
-  sfc = cairo_pdf_surface_create_for_stream (_write_func, obj,
+  sfc = cairo_pdf_surface_create_for_stream (_write_bytes_func, obj,
 					     width_in_points, height_in_points);
   Py_END_ALLOW_THREADS;
   return PycairoSurface_FromSurface (sfc, obj);
@@ -829,14 +849,14 @@ ps_surface_new (PyTypeObject *type, PyObject *args, PyObject *kwds) {
 "  None, or\n"
 "  a filename (str), or\n"
 "  a file object, or\n"
-"  an object that has a \"write\" method (like StringIO)."
+"  a file-like bytes-mode object which has a \"write\" method."
 		    );
     return NULL;
   }
   Py_DECREF(writer);
 
   Py_BEGIN_ALLOW_THREADS;
-  sfc = cairo_ps_surface_create_for_stream (_write_func, obj,
+  sfc = cairo_ps_surface_create_for_stream (_write_bytes_func, obj,
 					    width_in_points, height_in_points);
   Py_END_ALLOW_THREADS;
   return PycairoSurface_FromSurface (sfc, obj);
@@ -1121,14 +1141,14 @@ svg_surface_new (PyTypeObject *type, PyObject *args, PyObject *kwds) {
 "  None, or\n"
 "  a filename (str), or\n"
 "  a file object, or\n"
-"  an object that has a \"write\" method (like StringIO)."
+"  a file-like text-mode object which has a \"write\" method."
 		    );
     return NULL;
   }
   Py_DECREF(writer);
 
   Py_BEGIN_ALLOW_THREADS;
-  sfc = cairo_svg_surface_create_for_stream (_write_func, obj,
+  sfc = cairo_svg_surface_create_for_stream (_write_str_func, obj,
 					     width_in_points, height_in_points);
   Py_END_ALLOW_THREADS;
   return PycairoSurface_FromSurface (sfc, obj);
diff --git a/test/surface_create_for_stream.py b/test/surface_create_for_stream.py
index da543f2..b6ad225 100755
--- a/test/surface_create_for_stream.py
+++ b/test/surface_create_for_stream.py
@@ -3,11 +3,10 @@
 Test PDF/PS/SVG constructors (using streams)
 """
 
-import cStringIO
 import gc
 import math
 import sys
-import StringIO
+#import io.Bytes
 
 import cairo
 
@@ -28,22 +27,27 @@ class C(object):
     self.closed = True
 
 
+WIDTH, HEIGHT  = 256, 256
+
 # a selection of possible args to surface.write_to_png()
-#fo = '/tmp/f.ps'
-fo = file('/tmp/f.svg', 'wb')
-#fo = StringIO.StringIO()
-#fo = cStringIO.StringIO()
-#fo = sys.stdout
+fo = sys.stdout  # only compatible with str/text objects - SVG
 #fo = C()
 
-#fo.close()  # this should cause: ValueError: I/O operation on closed file
-
-WIDTH, HEIGHT  = 256, 256
-
+#fo = '/tmp/f.pdf'
+#fo = open('/tmp/f.pdf', 'wb')
 #surface = cairo.PDFSurface(fo, WIDTH, HEIGHT)
+
+#fo = '/tmp/f.ps'
+#fo = open('/tmp/f.ps', 'wb')
 #surface = cairo.PSSurface(fo, WIDTH, HEIGHT)
+
+#fo = '/tmp/f.svg'
+#fo = open('/tmp/f.svg', 'wt')
 surface = cairo.SVGSurface(fo, WIDTH, HEIGHT)
 
+#fo.close()  # this should cause: ValueError: I/O operation on closed file
+
+
 #sys.stdout.write ('1\n'); sys.stdout.flush()
 ctx = cairo.Context(surface)
 
@@ -74,7 +78,7 @@ ctx.fill()
 ctx.show_page()
 surface.finish()
 
-# for testing StringIO: get data and write to file
+# for testing io.Bytes: get data and write to file
 #string = fo.getvalue()
 #f2 = file('/tmp/f.ps', 'wb')
 #f2.write(string)