From e8e5e12ad29004714f04f3697a6fdfb7813602c1 Mon Sep 17 00:00:00 2001
From: Daniel Kirchner <daniel@ekpyron.org>
Date: Wed, 11 Jul 2018 15:30:54 +0200
Subject: [PATCH] Fix literals with exponents with mantissa of zero.

---
 libsolidity/ast/Types.cpp                     | 19 +++++++++++--------
 .../types/rational_number_exp_limit.sol       |  1 +
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 0a4f199dd..dd0736e95 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -771,7 +771,17 @@ tuple<bool, rational> RationalNumberType::isValidLiteral(Literal const& _literal
 		}
 		else if (expPoint != _literal.value().end())
 		{
-			// Parse base and exponent. Checks numeric limit.
+			// Parse mantissa and exponent. Checks numeric limit.
+			tuple<bool, rational> mantissa = parseRational(string(_literal.value().begin(), expPoint));
+
+			if (!get<0>(mantissa))
+				return make_tuple(false, rational(0));
+			value = get<1>(mantissa);
+
+			// 0E... is always zero.
+			if (value == 0)
+				return make_tuple(true, rational(0));
+
 			bigint exp = bigint(string(expPoint + 1, _literal.value().end()));
 
 			if (exp > numeric_limits<int32_t>::max() || exp < numeric_limits<int32_t>::min())
@@ -779,13 +789,6 @@ tuple<bool, rational> RationalNumberType::isValidLiteral(Literal const& _literal
 
 			uint32_t expAbs = bigint(abs(exp)).convert_to<uint32_t>();
 
-
-			tuple<bool, rational> base = parseRational(string(_literal.value().begin(), expPoint));
-
-			if (!get<0>(base))
-				return make_tuple(false, rational(0));
-			value = get<1>(base);
-
 			if (exp < 0)
 			{
 				if (!fitsPrecisionBase10(abs(value.denominator()), expAbs))
diff --git a/test/libsolidity/syntaxTests/types/rational_number_exp_limit.sol b/test/libsolidity/syntaxTests/types/rational_number_exp_limit.sol
index 6785f580a..217122055 100644
--- a/test/libsolidity/syntaxTests/types/rational_number_exp_limit.sol
+++ b/test/libsolidity/syntaxTests/types/rational_number_exp_limit.sol
@@ -19,6 +19,7 @@ contract c {
         a = 1E1233 ** -1E1233;
         a = -1E1233 ** 1E1233;
         a = -1E1233 ** -1E1233;
+        a = 0E123456789; // fine
     }
 }
 // ----