Removed ipc module.

There was only one function in module ipc: eintr_retry_call. This
function was used in pdftohtml module, and turns out[1] it's not needed
anymore. Support for retrying on syscall interrupts was introduced in
Python 3.5 (which was released in 2015), and covers subprocess module
among other modules. In this commit, mentioned eintr_retry_call function
has been removed, and couple of cosmetic changes was done in module
pdftohtml.

[1] https://www.python.org/dev/peps/pep-0475/

ebook_converter/ebooks/pdf/pdftohtml.py

@@ -12,7 +12,6 @@ from ebook_converter.ptempfile import PersistentTemporaryFile
 from ebook_converter.utils.cleantext import clean_xml_chars
 from ebook_converter.utils import directory
 from ebook_converter.utils import entities
-from ebook_converter.utils.ipc import eintr_retry_call
 
 
 def popen(cmd, **kw):
@@ -33,12 +32,8 @@ def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):
         shutil.copyfileobj(src, dest)
 
     with directory.CurrentDir(output_dir):
-
-        def a(x):
-            return os.path.basename(x)
-
         cmd = ['pdftohtml', '-enc', 'UTF-8', '-noframes', '-p', '-nomerge',
-               '-nodrm', a(pdfsrc), a(index)]
+               '-nodrm', os.path.basename(pdfsrc), os.path.basename(index)]
 
         if no_images:
             cmd.append('-i')
@@ -46,19 +41,22 @@ def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):
             cmd.append('-xml')
 
         logf = PersistentTemporaryFile('pdftohtml_log')
+
         try:
-            p = popen(cmd, stderr=logf._fd, stdout=logf._fd,
-                      stdin=subprocess.PIPE)
+            ret = subprocess.call(cmd, stderr=logf._fd, stdout=logf._fd)
         except OSError as err:
             if err.errno == errno.ENOENT:
                 raise ConversionError('Could not find pdftohtml, check it is '
                                       'in your PATH')
             else:
                 raise
-        ret = eintr_retry_call(p.wait)
+
         logf.flush()
         logf.close()
-        out = open(logf.name, 'rb').read().decode('utf-8', 'replace').strip()
+
+        with open(logf.name) as fobj:
+            out = fobj.read().strip()
+
         if ret != 0:
             raise ConversionError('pdftohtml failed with return code: '
                                   '%d\n%s' % (ret, out))
@@ -92,10 +90,10 @@ def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):
 
             cmd = ['pdftohtml', '-f', '1', '-l', '1', '-xml', '-i', '-enc',
                    'UTF-8', '-noframes', '-p', '-nomerge', '-nodrm', '-q',
-                   '-stdout', a(pdfsrc)]
-            p = popen(cmd, stdout=subprocess.PIPE)
-            raw = p.stdout.read().strip()
-            if p.wait() == 0 and raw:
+                   '-stdout', os.path.basename(pdfsrc)]
+
+            raw = subprocess.check_output(cmd).strip()
+            if raw:
                 parse_outline(raw, output_dir)
 
         try:

ebook_converter/utils/ipc/__init__.py

@@ -1,11 +0,0 @@
-import errno
-
-
-def eintr_retry_call(func, *args, **kwargs):
-    while True:
-        try:
-            return func(*args, **kwargs)
-        except EnvironmentError as e:
-            if getattr(e, 'errno', None) == errno.EINTR:
-                continue
-            raise