4 files changed, 58 insertions, 9 deletions
diff --git a/lib/stdlib/doc/src/lists.xml b/lib/stdlib/doc/src/lists.xml
index 7efafedc82..55227aaee5 100644
--- a/lib/stdlib/doc/src/lists.xml
+++ b/lib/stdlib/doc/src/lists.xml
@@ -838,14 +838,6 @@ splitwith(Pred, List) ->
 > <input>lists:subtract("123212", "212").</input>
 "312".</pre>
         <p><c>lists:subtract(A, B)</c> is equivalent to <c>A -- B</c>.</p>
-        <warning>
-          <p>The complexity of <c>lists:subtract(A, B)</c> is proportional to
-            <c>length(A)*length(B)</c>, meaning that it is very slow if both
-            <c>A</c> and <c>B</c> are long lists. (If both lists are long, it
-            is a much better choice to use ordered lists and
-            <seealso marker="ordsets#subtract/2">
-            <c>ordsets:subtract/2</c></seealso>.</p>
-        </warning>
       </desc>
     </func>
 
diff --git a/lib/stdlib/doc/src/notes.xml b/lib/stdlib/doc/src/notes.xml
index e26c4aba74..3c7c8bf400 100644
--- a/lib/stdlib/doc/src/notes.xml
+++ b/lib/stdlib/doc/src/notes.xml
@@ -31,6 +31,21 @@
   </header>
   <p>This document describes the changes made to the STDLIB application.</p>
 
+<section><title>STDLIB 3.4.5.1</title>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+	    <p>List subtraction (The <c>--</c> operator) will now
+	    yield properly on large inputs.</p>
+          <p>
+	    Own Id: OTP-15371</p>
+        </item>
+      </list>
+    </section>
+
+</section>
+
 <section><title>STDLIB 3.4.5</title>
 
     <section><title>Fixed Bugs and Malfunctions</title>
diff --git a/lib/stdlib/test/lists_SUITE.erl b/lib/stdlib/test/lists_SUITE.erl
index 7c99244b36..c380b3bba1 100644
--- a/lib/stdlib/test/lists_SUITE.erl
+++ b/lib/stdlib/test/lists_SUITE.erl
@@ -2597,6 +2597,13 @@ subtract(Config) when is_list(Config) ->
     {'EXIT',_} = (catch sub([a|b], [])),
     {'EXIT',_} = (catch sub([a|b], [a])),
 
+    %% Trapping, both crashing and otherwise.
+    [sub_trapping(N) || N <- lists:seq(0, 18)],
+
+    %% The current implementation chooses which algorithm to use based on
+    %% certain thresholds, and we need proper coverage for all corner cases.
+    [sub_thresholds(N) || N <- lists:seq(0, 32)],
+
     ok.
 
 sub_non_matching(A, B) ->
@@ -2606,6 +2613,41 @@ sub(A, B) ->
     Res = A -- B,
     Res = lists:subtract(A, B).
 
+sub_trapping(N) ->
+    List = lists:duplicate(N + (1 bsl N), gurka),
+    ImproperList = List ++ crash,
+
+    {'EXIT',_} = (catch sub_trapping_1(ImproperList, [])),
+    {'EXIT',_} = (catch sub_trapping_1(List, ImproperList)),
+
+    List = List -- lists:duplicate(N + (1 bsl N), gaffel),
+    ok = sub_trapping_1(List, []).
+
+sub_trapping_1([], _) -> ok;
+sub_trapping_1(L, R) -> sub_trapping_1(L -- R, [gurka | R]).
+
+sub_thresholds(N) ->
+    %% This needs to be long enough to cause trapping.
+    OtherLen = 1 bsl 18,
+    Other = lists:seq(0, OtherLen - 1),
+
+    Disjoint = lists:seq(-N, -1),
+    Subset = lists:seq(1, N),
+
+    %% LHS is disjoint from RHS, so all elements must be retained.
+    Disjoint = Disjoint -- Other,
+
+    %% LHS is covered by RHS, so all elements must be removed.
+    [] = Subset -- Other,
+
+    %% RHS is disjoint from LHS, so all elements must be retained.
+    Other = Other -- Disjoint,
+
+    %% RHS is covered by LHS, so N elements must be removed.
+    N = OtherLen - length(Other -- Subset),
+
+    ok.
+
 %% Test lists:droplast/1
 droplast(Config) when is_list(Config) ->
     [] = lists:droplast([x]),
diff --git a/lib/stdlib/vsn.mk b/lib/stdlib/vsn.mk
index 09a4d6fb50..34ba8c083d 100644
--- a/lib/stdlib/vsn.mk
+++ b/lib/stdlib/vsn.mk
@@ -1 +1 @@
-STDLIB_VSN = 3.4.5
+STDLIB_VSN = 3.4.5.1