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-rw-r--r--lib/dialyzer/test/small_SUITE_data/src/inv_mult.erl15
1 files changed, 15 insertions, 0 deletions
diff --git a/lib/dialyzer/test/small_SUITE_data/src/inv_mult.erl b/lib/dialyzer/test/small_SUITE_data/src/inv_mult.erl
new file mode 100644
index 0000000000..3413556813
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/inv_mult.erl
@@ -0,0 +1,15 @@
+%% Dialyzer was too constraining when checking the relation between the
+%% arguments and result of a multiplication. We should not constrain an argument
+%% if the other operand *may* be zero.
+%%
+%% Bug found by Kostis Sagonas, fixed by Stavros Aronis
+
+-module(inv_mult).
+-compile(export_all).
+
+main(L) ->
+ N = -1 * length(L),
+ fact(N).
+
+fact(0) -> 1;
+fact(N) -> N * fact(N-1).