[PATCH stable] convert.cvs: Initialize state variable

[Frank Kingswood]

Mads Kiilerich wrote:

> Ok. But I am -2 on having code paths where external input (no matter how 
> unexpected and wrong) can cause use of uninitialized variables and crashes.
> 
> Why should data be initialized when mode isn't?
> 
> Initializing mode might not make the code correct, but it removes one 
> problem.
> 
> How about something like
> 
> diff --git a/hgext/convert/cvs.py b/hgext/convert/cvs.py
> --- a/hgext/convert/cvs.py
> +++ b/hgext/convert/cvs.py
> @@ -226,7 +226,8 @@
>          self.writep.write("Directory .\n%s\nco\n" % self.realroot)
>          self.writep.flush()
> 
> -        data = ""
> +        data = None
> +        mode = ""
>          while 1:
>              line = self.readp.readline()
>              if line.startswith("Created ") or line.startswith("Updated "):
> @@ -244,6 +245,8 @@
>                  data = chunkedread(self.readp, count)
>              else:
>                  if line == "ok\n":
> +                    if data is None:
> +                        raise util.Abort(_('CVS response "ok" without 
> data'))
>                      return (data, "x" in mode and "x" or "")

That creates a new problem in cases where we hit
	data += line[1:]
(when data is None)

How about

--- a/hgext/convert/cvs.py	Wed Mar 10 12:38:33 2010 +0100
+++ b/hgext/convert/cvs.py	Wed Mar 24 16:06:43 2010 +0000
@@ -227,6 +227,7 @@
          self.writep.flush()

          data = ""
+        mode = None
          while 1:
              line = self.readp.readline()
              if line.startswith("Created ") or line.startswith("Updated "):
@@ -244,6 +245,8 @@
                  data = chunkedread(self.readp, count)
              else:
                  if line == "ok\n":
+                    if mode is None:
+                        raise util.Abort(_('malformed response from CVS'))
                      return (data, "x" in mode and "x" or "")
                  elif line.startswith("E "):
                      self.ui.warn(_("cvs server: %s\n") % line[2:])