Constify the reason string throughout the authorization check framework

Almost all of the places the string is assigned point to a literal
string constant, so use const char * for those, and const char **
for function calls that return it via an argument.   Fortunately
the top level function, ClientAuthorized, which returns the string
as its return value is called from only one place, ProcEstablishConnection.

ProcEstablishConnection stores either that return value or a string literal
in char *reason.  It only uses reason as an argument to SendConnSetup.
SendConnSetup passes the reason argument to strlen & WriteToClient,
both of which already have const qualifiers on their args.
Thus added const to the reason variable in ProcEstablishConnection
and the reason argument to SendConnSetup.

Fixes gcc warnings:
dispatch.c: In function 'ProcEstablishConnection':
dispatch.c:3711:9: warning: assignment discards qualifiers from pointer target type
auth.c: In function 'CheckAuthorization':
auth.c:218:14: warning: assignment discards qualifiers from pointer target type
auth.c:220:20: warning: assignment discards qualifiers from pointer target type
connection.c: In function 'ClientAuthorized':
connection.c:683:3: warning: return discards qualifiers from pointer target type
mitauth.c: In function 'MitCheckCookie':
mitauth.c:88:13: warning: assignment discards qualifiers from pointer target type
xdmauth.c:259:14: warning: assignment discards qualifiers from pointer target type
xdmauth.c:270:14: warning: assignment discards qualifiers from pointer target type
xdmauth.c:277:11: warning: assignment discards qualifiers from pointer target type
xdmauth.c:293:15: warning: assignment discards qualifiers from pointer target type
xdmauth.c:313:14: warning: assignment discards qualifiers from pointer target type
xdmauth.c:322:11: warning: assignment discards qualifiers from pointer target type
rpcauth.c: In function 'SecureRPCCheck':
rpcauth.c:136:10: warning: assignment discards qualifiers from pointer target type

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/os.h b/include/os.h
index 0b5024156..48ce32962 100644
--- a/include/os.h
+++ b/include/os.h
@@ -127,7 +127,7 @@ extern _X_EXPORT void CloseWellKnownConnections(void);
 
 extern _X_EXPORT XID AuthorizationIDOfClient(ClientPtr /*client*/);
 
-extern _X_EXPORT char *ClientAuthorized(
+extern _X_EXPORT const char *ClientAuthorized(
     ClientPtr /*client*/,
     unsigned int /*proto_n*/,
     char* /*auth_proto*/,
@@ -415,7 +415,7 @@ extern _X_EXPORT XID CheckAuthorization(
     unsigned int /*datalength*/,
     const char * /*data*/,
     ClientPtr /*client*/,
-    char ** /*reason*/
+    const char ** /*reason*/
 );
 
 extern _X_EXPORT void ResetAuthorization(void);