Move to Python 3

Python 3 was released more than 10 years ago, and support for Python 2
is going away, with many Linux distributions starting to phase it out.

This patch migrates git-arr to Python 3.

The generated output is almost exactly the same, there are some minor
differences such as HTML characters being quoted more aggresively, and
handling of paths with non-utf8 values.

1 files changed, 38 insertions, 49 deletions

diff --git a/git.py b/git.py
index 2240175..09ccd37 100644
--- a/git.py
+++ b/git.py
@@ -12,35 +12,13 @@ import subprocess
 from collections import defaultdict
 import email.utils
 import datetime
-import urllib
-from cgi import escape
+import urllib.request, urllib.parse, urllib.error
+from html import escape
 
 
 # Path to the git binary.
 GIT_BIN = "git"
 
-class EncodeWrapper:
-    """File-like wrapper that returns data utf8 encoded."""
-    def __init__(self, fd, encoding = 'utf8', errors = 'replace'):
-        self.fd = fd
-        self.encoding = encoding
-        self.errors = errors
-
-    def __iter__(self):
-        for line in self.fd:
-            yield line.decode(self.encoding, errors = self.errors)
-
-    def read(self):
-        """Returns the whole content."""
-        s = self.fd.read()
-        return s.decode(self.encoding, errors = self.errors)
-
-    def readline(self):
-        """Returns a single line."""
-        s = self.fd.readline()
-        return s.decode(self.encoding, errors = self.errors)
-
-
 def run_git(repo_path, params, stdin = None, silent_stderr = False, raw = False):
     """Invokes git with the given parameters.
 
@@ -66,13 +44,8 @@ def run_git(repo_path, params, stdin = None, silent_stderr = False, raw = False)
     if raw:
         return p.stdout
 
-    # We need to wrap stdout if we want to decode it as utf8, subprocess
-    # doesn't support us telling it the encoding.
-    if sys.version_info.major == 3:
-        return io.TextIOWrapper(p.stdout, encoding = 'utf8',
-                errors = 'replace')
-    else:
-        return EncodeWrapper(p.stdout)
+    return io.TextIOWrapper(p.stdout, encoding = 'utf8',
+            errors = 'backslashreplace')
 
 
 class GitCommand (object):
@@ -109,6 +82,8 @@ class GitCommand (object):
     def stdin(self, s):
         """Sets the contents we will send in stdin."""
         self._override = True
+        if isinstance(s, str):
+            s = s.encode("utf8")
         self._stdin_buf = s
         self._override = False
 
@@ -116,7 +91,7 @@ class GitCommand (object):
         """Runs the git command."""
         params = [self._cmd]
 
-        for k, v in self._kwargs.items():
+        for k, v in list(self._kwargs.items()):
             dash = '--' if len(k) > 1 else '-'
             if v is None:
                 params.append('%s%s' % (dash, k))
@@ -146,11 +121,16 @@ class smstr:
         .html    -> an HTML-embeddable representation.
     """
     def __init__(self, raw):
-        if not isinstance(raw, str):
-            raise TypeError("The raw string must be instance of 'str'")
+        if not isinstance(raw, (str, bytes)):
+            raise TypeError(
+                    "The raw string must be instance of 'str', not %s" %
+                    type(raw))
         self.raw = raw
-        self.unicode = raw.decode('utf8', errors = 'replace')
-        self.url = urllib.pathname2url(raw)
+        if isinstance(raw, bytes):
+            self.unicode = raw.decode('utf8', errors = 'backslashreplace')
+        else:
+            self.unicode = raw
+        self.url = urllib.request.pathname2url(raw)
         self.html = self._to_html()
 
     def __cmp__(self, other):
@@ -163,7 +143,7 @@ class smstr:
     @staticmethod
     def from_url(url):
         """Returns an smstr() instance from an url-encoded string."""
-        return smstr(urllib.url2pathname(url))
+        return smstr(urllib.request.url2pathname(url))
 
     def split(self, sep):
         """Like str.split()."""
@@ -176,10 +156,10 @@ class smstr:
 
     def _to_html(self):
         """Returns an html representation of the unicode string."""
-        html = u''
+        html = ''
         for c in escape(self.unicode):
             if c in '\t\r\n\r\f\a\b\v\0':
-                esc_c = c.encode('ascii').encode('string_escape')
+                esc_c = c.encode("unicode-escape").decode("utf8")
                 html += '<span class="ctrlchr">%s</span>' % esc_c
             else:
                 html += c
@@ -190,14 +170,23 @@ class smstr:
 def unquote(s):
     """Git can return quoted file names, unquote them. Always return a str."""
     if not (s[0] == '"' and s[-1] == '"'):
-        # Unquoted strings are always safe, no need to mess with them; just
-        # make sure we return str.
-        s = s.encode('ascii')
+        # Unquoted strings are always safe, no need to mess with them
         return s
 
-    # Get rid of the quotes, we never want them in the output, and convert to
-    # a raw string, un-escaping the backslashes.
-    s = s[1:-1].decode('string-escape')
+    # The string will be of the form `"<escaped>"`, where <escaped> is a
+    # backslash-escaped representation of the name of the file.
+    # Examples:  "with\ttwo\ttabs" , "\303\261aca-utf8", "\361aca-latin1"
+
+    # Get rid of the quotes, we never want them in the output.
+    s = s[1:-1]
+
+    # Un-escape the backslashes.
+    # latin1 is ok to use here because in Python it just maps the code points
+    # 0-255 to the bytes 0x-0xff, which is what we expect.
+    s = s.encode("latin1").decode("unicode-escape")
+
+    # Convert to utf8.
+    s = s.encode("latin1").decode("utf8", errors='backslashreplace')
 
     return s
 
@@ -337,13 +326,13 @@ class Repo:
         cmd.raw(True)
         cmd.batch = '%(objectsize)'
 
-        if isinstance(ref, unicode):
-            ref = ref.encode('utf8')
-        cmd.stdin('%s:%s' % (ref, path))
+        # Format: <ref>:<path>
+        # Construct it in binary since the path might not be utf8.
+        cmd.stdin(ref.encode("utf8") + b":" + path)
 
         out = cmd.run()
         head = out.readline()
-        if not head or head.strip().endswith('missing'):
+        if not head or head.strip().endswith(b'missing'):
             return None
 
         return Blob(out.read()[:int(head)])