diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c6a6d8f5522..621da5be476 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2012-02-29  Joel Brobecker  <brobecker@adacore.com>
+
+	* ada-lex.p (processId): Do not modify already encoded IDs.
+	Update function documentation.
+
 2012-02-29  Joel Brobecker  <brobecker@adacore.com>
 
 	* ada-lang.h (ada_find_renaming_symbol): Replace parameter
diff --git a/gdb/ada-lex.l b/gdb/ada-lex.l
index 48667d062b5..5102ff49f59 100644
--- a/gdb/ada-lex.l
+++ b/gdb/ada-lex.l
@@ -410,7 +410,9 @@ processReal (const char *num0)
 
 
 /* Store a canonicalized version of NAME0[0..LEN-1] in yylval.ssym.  The
-   resulting string is valid until the next call to ada_parse.  It differs
+   resulting string is valid until the next call to ada_parse.  If
+   NAME0 contains the substring "___", it is assumed to be already
+   encoded and the resulting name is equal to it.  Otherwise, it differs
    from NAME0 in that:
     + Characters between '...' or <...> are transfered verbatim to 
       yylval.ssym.
@@ -430,8 +432,18 @@ processId (const char *name0, int len)
   int i0, i;
   struct stoken result;
 
+  result.ptr = name;
   while (len > 0 && isspace (name0[len-1]))
     len -= 1;
+
+  if (strstr (name0, "___") != NULL)
+    {
+      strncpy (name, name0, len);
+      name[len] = '\000';
+      result.length = len;
+      return result;
+    }
+
   i = i0 = 0;
   while (i0 < len)
     {
@@ -471,7 +483,6 @@ processId (const char *name0, int len)
     }
   name[i] = '\000';
 
-  result.ptr = name;
   result.length = i;
   return result;
 }