RandomGenerator: Fix except = start and except = end edge cases

Author: adazem009

src/engine/internal/randomgenerator.cpp

@@ -57,13 +57,12 @@ long RandomGenerator::randintExcept(long start, long end, long except) const
             return end;
         else
             return start;
-    }
-
-    if (randint(0, 1) == 0) {
-        std::uniform_int_distribution<long> distribution(start, except - 1);
-        return distribution(*m_generator);
-    } else {
-        std::uniform_int_distribution<long> distribution(except + 1, end);
-        return distribution(*m_generator);
-    }
+    } else if (except == start)
+        return randint(except + 1, end);
+    else if (except == end)
+        return randint(start, except - 1);
+    else if (randint(0, 1) == 0)
+        return randint(start, except - 1);
+    else
+        return randint(except + 1, end);
 }

test/randomgenerator/randomgenerator_test.cpp

@@ -96,4 +96,16 @@ TEST(RandomGeneratorTest, RandIntExcept)
         num = rng->randintExcept(1, 2, 2);
         ASSERT_EQ(num, 1);
     }
+
+    for (int i = 0; i < 25; i++) {
+        num = rng->randintExcept(1, 5, 1);
+        ASSERT_GE(num, 2);
+        ASSERT_LE(num, 5);
+    }
+
+    for (int i = 0; i < 25; i++) {
+        num = rng->randintExcept(1, 5, 5);
+        ASSERT_GE(num, 1);
+        ASSERT_LE(num, 4);
+    }
 }