Fix #5811 as suggested. (Merge 13792 from 4.01.)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13793 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

2 files changed, 3 insertions, 0 deletions

diff --git a/Changes b/Changes
index 8caf9c47e..e4d82539a 100644
--- a/Changes
+++ b/Changes
@@ -103,6 +103,8 @@ Bug fixes:
 - PR#5805: Assert failure with warning 34 on pre-processed file
 - PR#5806: ensure that backtrace tests are always run (testsuite)
 - PR#5810: error in switch printing when using -dclambda
+- PR#5811: Untypeast produces singleton tuples for constructor patterns
+  with only one argument
 - PR#5813: GC not called when unmarshaling repeatedly in a tight loop (ocamlopt)
 - PR#5815: Multiple exceptions in signatures gives an error
 - PR#5819: segfault when using [with] on large recursive record (ocamlopt)
diff --git a/tools/untypeast.ml b/tools/untypeast.ml
index a0b1a2c1e..e1719d903 100644
--- a/tools/untypeast.ml
+++ b/tools/untypeast.ml
@@ -153,6 +153,7 @@ and untype_pattern pat =
         Ppat_construct (lid,
           (match args with
               [] -> None
+            | [arg] -> Some (untype_pattern arg)
             | args -> Some
                   { ppat_desc = Ppat_tuple (List.map untype_pattern args);
                   ppat_loc = pat.pat_loc; }