[PATCH 2/2] cygheap_pwdgrp: Don't keep old schemes when parsing nsswitch.conf

[Corinna Vinschen]

On Apr 17 11:31, David Macek via Cygwin-patches wrote:
> The implicit assumption seemed to be that any subsequent occurence of
> the same setting in nsswitch.conf is supposed to rewrite the previous
> ones completely.  This was not the case if the third or any further
> schema was previously defined and the last line defined less than that
> (but at least 2), for example:
> 
> ```
> db_home: windows cygwin /myhome/%U
> db_home: cygwin desc
> ```
> 
> Let's document this behavior as well.
> ---
>  winsup/cygwin/uinfo.cc | 5 +++--
>  winsup/doc/ntsec.xml   | 5 +++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
> index 227faa4248..a4fcc33d8d 100644
> --- a/winsup/cygwin/uinfo.cc
> +++ b/winsup/cygwin/uinfo.cc
> @@ -793,9 +793,10 @@ cygheap_pwdgrp::nss_init_line (const char *line)
>  	    scheme = gecos_scheme;
>  	  if (scheme)
>  	    {
> -	      uint16_t idx = 0;
> +	      for (uint16_t idx = 0; idx < NSS_SCHEME_MAX; ++idx)
> +		scheme[idx].method = NSS_SCHEME_FALLBACK;
>  
> -	      scheme[0].method = scheme[1].method = NSS_SCHEME_FALLBACK;
> +	      uint16_t idx = 0;

Hmmm.  This `idx' usage is a bit puzzeling.  Here's a counter-proposal:

diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
index 57d90189d390..9521a973803e 100644
--- a/winsup/cygwin/uinfo.cc
+++ b/winsup/cygwin/uinfo.cc
@@ -793,12 +793,12 @@ cygheap_pwdgrp::nss_init_line (const char *line)
 	    scheme = gecos_scheme;
 	  if (scheme)
 	    {
-	      uint16_t idx = 0;
+	      for (uint16_t idx = 0; idx < NSS_SCHEME_MAX; ++idx)
+		scheme[idx].method = NSS_SCHEME_FALLBACK;
 
-	      scheme[0].method = scheme[1].method = NSS_SCHEME_FALLBACK;
 	      c = strchr (c, ':') + 1;
 	      c += strspn (c, " \t");
-	      while (*c && idx < NSS_SCHEME_MAX)
+	      for (uint16_t idx = 0; *c && idx < NSS_SCHEME_MAX; ++idx)
 		{
 		  if (NSS_CMP ("windows"))
 		    scheme[idx].method = NSS_SCHEME_WINDOWS;
@@ -829,7 +829,6 @@ cygheap_pwdgrp::nss_init_line (const char *line)
 		    }
 		  c += strcspn (c, " \t");
 		  c += strspn (c, " \t");
-		  ++idx;
 		}
 	      /* If nothing has been set, revert to default. */
 	      if (scheme[0].method == NSS_SCHEME_FALLBACK)

If that's ok with you I check it in as your patch.

Can you please send the 2-clause BSD waiver per
https://cygwin.com/contrib.html to this list, too?


Thanks,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
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