[Ada] Fix PR ada/70786

[Eric Botcazou]

It's a small pasto in one of the variants of Get_Immediate.

Tested on x86_64-suse-linux, applied on all active branches.


2016-04-28  Eric Botcazou  <ebotca...@adacore.com>

        PR ada/70786
        * a-textio.adb (Get_Immediate): Add missing 'not' in expression.


-- 
Eric Botcazou

Index: a-textio.adb
===================================================================
--- a-textio.adb	(revision 235544)
+++ a-textio.adb	(working copy)
@@ -668,7 +668,7 @@ package body Ada.Text_IO is
             Available := True;
 
             Item :=
-              (if Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
+              (if not Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
                then Character'Val (ch)
                else Get_Upper_Half_Char_Immed (Character'Val (ch), File));
          end if;