fix zip file corruption

lib/extensions/output.py

@@ -35,12 +35,14 @@ class Output(InkstitchExtension):
         # in windows, failure to close here will keep the file locked
         temp_file.close()
 
+        # libembroidery likes to debug log things to stdout.  No way to disable it.
+        save_stdout()
         write_embroidery_file(temp_file.name, stitch_plan, self.document.getroot())
 
         # inkscape will read the file contents from stdout and copy
         # to the destination file that the user chose
         with open(temp_file.name) as output_file:
-            sys.stdout.write(output_file.read())
+            sys.real_stdout.write(output_file.read())
 
         # clean up the temp file
         os.remove(temp_file.name)

lib/extensions/zip.py

@@ -11,6 +11,7 @@ from ..i18n import _
 from ..output import write_embroidery_file
 from ..stitch_plan import patches_to_stitch_plan
 from ..svg import render_stitch_plan, PIXELS_PER_MM
+from ..utils.io import save_stdout
 
 
 class Zip(InkstitchExtension):
@@ -48,12 +49,19 @@ class Zip(InkstitchExtension):
 
         files = []
 
+        # libembroidery likes to debug log things to stdout.  No way to disable it.
+        save_stdout()
         for format in self.formats:
             if getattr(self.options, format):
                 output_file = os.path.join(path, "%s.%s" % (base_file_name, format))
                 write_embroidery_file(output_file, stitch_plan, self.document.getroot())
                 files.append(output_file)
 
+        # I'd love to do restore_stderr() here, but if I do, libembroidery's
+        # stuff still prints out and corrupts the zip!  That's because it uses
+        # C's buffered stdout, so it hasn't actually written anything to the
+        # real standard output yet.
+
         if not files:
             self.errormsg(_("No embroidery file formats selected."))
 
@@ -69,7 +77,7 @@ class Zip(InkstitchExtension):
         # inkscape will read the file contents from stdout and copy
         # to the destination file that the user chose
         with open(temp_file.name) as output_file:
-            sys.stdout.write(output_file.read())
+            sys.real_stdout.write(output_file.read())
 
         os.remove(temp_file.name)
         for file in files:

lib/utils/io.py

@@ -7,12 +7,31 @@ def save_stderr():
     # GTK likes to spam stderr, which inkscape will show in a dialog.
     null = open(os.devnull, 'w')
     sys.stderr_dup = os.dup(sys.stderr.fileno())
+    sys.real_stderr = os.fdopen(sys.stderr_dup, 'w')
     os.dup2(null.fileno(), 2)
     sys.stderr_backup = sys.stderr
     sys.stderr = StringIO()
 
 
 def restore_stderr():
+    sys.real_stderr.close()
     os.dup2(sys.stderr_dup, 2)
-    sys.stderr_backup.write(sys.stderr.getvalue())
+    sys.real_stderr.write(sys.stderr.getvalue())
     sys.stderr = sys.stderr_backup
+
+# It's probably possible to generalize this code, but when I tried,
+# the result was incredibly unreadable.
+def save_stdout():
+    null = open(os.devnull, 'w')
+    sys.stdout_dup = os.dup(sys.stdout.fileno())
+    sys.real_stdout = os.fdopen(sys.stdout_dup, 'w')
+    os.dup2(null.fileno(), 1)
+    sys.stdout_backup = sys.stdout
+    sys.stdout = StringIO()
+
+
+def restore_stdout():
+    sys.real_stdout.close()
+    os.dup2(sys.stdout_dup, 1)
+    sys.real_stdout.write(sys.stdout.getvalue())
+    sys.stdout = sys.stdout_backup