From ef0d216f662327316c26072412f591f342a7312e Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Thu, 4 Apr 2019 16:40:28 -0500
Subject: [PATCH] Fix float_endf for decimal-less numbers. Also secretly
 support d/D

---
 openmc/data/endf.c            | 12 +++++++-----
 tests/unit_tests/test_endf.py | 11 +++++++++++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/openmc/data/endf.c b/openmc/data/endf.c
index b83e130c73..fee6af179e 100644
--- a/openmc/data/endf.c
+++ b/openmc/data/endf.c
@@ -4,14 +4,14 @@ double cfloat_endf(const char* buffer, int n)
 {
   char arr[12]; // 11 characters plus a null terminator
   int j = 0; // current position in arr
-  int found_decimal = 0;
+  int found_significand = 0;
   int found_exponent = 0;
   for (int i = 0; i < n; ++i) {
     // Skip whitespace characters
     char c = buffer[i];
     if (c == ' ') continue;
 
-    if (found_decimal) {
+    if (found_significand) {
       if (!found_exponent) {
         if (c == '+' || c == '-') {
           // In the case that we encounter +/- and we haven't yet encountered
@@ -19,12 +19,14 @@ double cfloat_endf(const char* buffer, int n)
           arr[j++] = 'e';
           found_exponent = 1;
 
-        } else if (c == 'e' || c == 'E') {
+        } else if (c == 'e' || c == 'E' || c == 'd' || c == 'D') {
+          arr[j++] = 'e';
           found_exponent = 1;
+          continue;
         }
       }
-    } else if (c == '.') {
-      found_decimal = 1;
+    } else if (c == '.' || (c >= '0' && c <= '9')) {
+      found_significand = 1;
     }
 
     // Copy character
diff --git a/tests/unit_tests/test_endf.py b/tests/unit_tests/test_endf.py
index b6f79291de..11a8db4432 100644
--- a/tests/unit_tests/test_endf.py
+++ b/tests/unit_tests/test_endf.py
@@ -11,6 +11,17 @@ def test_float_endf():
     assert endf.float_endf(' -1.01- 2') == approx(-0.0101)
     assert endf.float_endf('+ 2 . 3+ 1') == approx(23.0)
     assert endf.float_endf('-7 .8 -1') == approx(-0.78)
+    assert endf.float_endf('3.14e0') == approx(3.14)
+    assert endf.float_endf('3.14E0') == approx(3.14)
+    assert endf.float_endf('3.14e-1') == approx(0.314)
+    assert endf.float_endf('3.14d0') == approx(3.14)
+    assert endf.float_endf('3.14D0') == approx(3.14)
+    assert endf.float_endf('3.14d-1') == approx(0.314)
+    assert endf.float_endf('1+2') == approx(100.0)
+    assert endf.float_endf('-1+2') == approx(-100.0)
+    assert endf.float_endf('1.+2') == approx(100.0)
+    assert endf.float_endf('-1.+2') == approx(-100.0)
+    assert endf.float_endf('        ') == 0.0
 
 
 def test_int_endf():