Re: [PATCH] fix compiler warnings in hurd/nfs and hurd/nfsd

[Flavio Cruz]

On Tue, Dec 29, 2015 at 11:17:12PM +0100, Samuel Thibault wrote:
> Flavio Cruz, on Tue 29 Dec 2015 23:10:44 +0100, wrote:
> > ---
> 
> Oops, no: I meant the *comment* after the ---, the changelog has to go
> before the ---, that's where git am picks it up.
> 
> > @@ -72,7 +72,7 @@ init_filesystems (void)
> >  
> >    for (line = 1; ; line++)
> >      {
> > -      nitems = fscanf (index_file, "%d %as\n", &index, &name);
> > +      nitems = fscanf (index_file, "%d %as\n", &index, (float *)&name);
> 
> I'm pretty sure that wasn't the original purpose :) I guess the 'a'
> qualifier is meant to mean 'allocate whatever size is needed'.

Looks like %a is now used for floats (that's why I blindly added the cast).
The recommended way described in 
http://man7.org/linux/man-pages/man3/scanf.3.html is to use %ms:

"The use of the letter a for this purpose was problematic, since a is
also specified by the ISO C standard as a synonym for f (floating- point
input). POSIX.1-2008 instead specifies the m modifier for assignment
allocation (as documented in DESCRIPTION, above)."

I guess this will probably fix a bug in the code :)


---
diff --git a/nfsd/fsys.c b/nfsd/fsys.c
index 7b15d15..f746716 100644
--- a/nfsd/fsys.c
+++ b/nfsd/fsys.c
@@ -72,7 +72,7 @@ init_filesystems (void)
 
   for (line = 1; ; line++)
     {
-      nitems = fscanf (index_file, "%d %as\n", &index, &name);
+      nitems = fscanf (index_file, "%d %ms\n", &index, &name);
       if (nitems == EOF)
        {
          fclose (index_file);