From 33a20b93f5dcc80596e3bfcf2990d2a913063bd5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Thu, 4 Jul 2019 11:19:19 +0200
Subject: [PATCH] [poincare] Log + negative argument gives unreal if
 complexFormat=real

---
 poincare/src/logarithm.cpp | 12 ++++++++----
 poincare/test/complex.cpp  |  2 +-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/poincare/src/logarithm.cpp b/poincare/src/logarithm.cpp
index 2386e4084..4d621ca6f 100644
--- a/poincare/src/logarithm.cpp
+++ b/poincare/src/logarithm.cpp
@@ -1,19 +1,18 @@
 #include <poincare/logarithm.h>
-
 #include <poincare/addition.h>
 #include <poincare/approximation_helper.h>
 #include <poincare/arithmetic.h>
+#include <poincare/constant.h>
 #include <poincare/division.h>
 #include <poincare/infinity.h>
+#include <poincare/layout_helper.h>
 #include <poincare/multiplication.h>
 #include <poincare/naperian_logarithm.h>
 #include <poincare/power.h>
 #include <poincare/rational.h>
-#include <poincare/layout_helper.h>
 #include <poincare/serialization_helper.h>
-
-#include <poincare/constant.h>
 #include <poincare/undefined.h>
+#include <poincare/unreal.h>
 #include <cmath>
 #include <ion.h>
 #include <assert.h>
@@ -118,6 +117,11 @@ Expression Logarithm::shallowReduce(ExpressionNode::ReductionContext reductionCo
   if (c.sign(reductionContext.context()) == ExpressionNode::Sign::Negative
       || childAtIndex(1).sign(reductionContext.context()) == ExpressionNode::Sign::Negative)
   {
+    if (reductionContext.complexFormat() == Preferences::ComplexFormat::Real) {
+      Expression result = Unreal::Builder();
+      replaceWithInPlace(result);
+      return result;
+    }
     return *this;
   }
   Expression f = simpleShallowReduce(reductionContext.context(), reductionContext.complexFormat(), reductionContext.angleUnit());
diff --git a/poincare/test/complex.cpp b/poincare/test/complex.cpp
index 9ae0a374c..2f24eab66 100644
--- a/poincare/test/complex.cpp
+++ b/poincare/test/complex.cpp
@@ -40,7 +40,7 @@ QUIZ_CASE(poincare_complex_simplify) {
   assert_parsed_expression_simplify_to("𝐢", "unreal", User, Radian, Real);
   assert_parsed_expression_simplify_to("√(-1)", "unreal", User, Radian, Real);
   assert_parsed_expression_simplify_to("√(-1)×√(-1)", "unreal", User, Radian, Real);
-  assert_parsed_expression_simplify_to("ln(-2)", "ln(-2)", User, Radian, Real);
+  assert_parsed_expression_simplify_to("ln(-2)", "unreal", User, Radian, Real);
   assert_parsed_expression_simplify_to("(-8)^(2/3)", "4", User, Radian, Real);
   assert_parsed_expression_simplify_to("(-8)^(2/5)", "2×root(2,5)", User, Radian, Real);
   assert_parsed_expression_simplify_to("(-8)^(1/5)", "-root(8,5)", User, Radian, Real);