Fixup integer conversion logic.

core/fxcrt/fx_basic_util_unittest.cpp

Index: core/fxcrt/fx_basic_util_unittest.cpp
diff --git a/core/fxcrt/fx_basic_util_unittest.cpp b/core/fxcrt/fx_basic_util_unittest.cpp
index 3272eab70c27439cfcb8c99fc8aede009e1aa3f9..6eae6696ad05b4adb8c64939658610f643420149 100644
--- a/core/fxcrt/fx_basic_util_unittest.cpp
+++ b/core/fxcrt/fx_basic_util_unittest.cpp
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <limits>
+
 #include "core/fxcrt/include/fx_basic.h"
 #include "testing/fx_string_testhelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -28,3 +30,48 @@ TEST(fxge, GetBits32) {
     }
   }
 }
+
+TEST(fxcrt, FX_atonum) {
+  int i;
+  EXPECT_TRUE(FX_atonum("10", &i));
+  EXPECT_EQ(10, i);
+
+  EXPECT_TRUE(FX_atonum("-10", &i));
+  EXPECT_EQ(-10, i);
+
+  EXPECT_TRUE(FX_atonum("+10", &i));
+  EXPECT_EQ(10, i);
+
+  EXPECT_TRUE(FX_atonum("-2147483648", &i));
+  EXPECT_EQ(std::numeric_limits<int>::min(), i);
+
+  EXPECT_TRUE(FX_atonum("2147483647", &i));
+  EXPECT_EQ(2147483647, i);
+
+  // Value overflows.
+  EXPECT_TRUE(FX_atonum("-2147483649", &i));
+  EXPECT_EQ(0, i);
+
+  // Value overflows.
+  EXPECT_TRUE(FX_atonum("+2147483648", &i));
+  EXPECT_EQ(0, i);
+
+  // Value overflows.
+  EXPECT_TRUE(FX_atonum("4223423494965252", &i));
+  EXPECT_EQ(0, i);
+
+  // No explicit sign will allow the number to go negative. This is for things
+  // like the encryption Permissions flag (Table 3.20 PDF 1.7 spec)
+  EXPECT_TRUE(FX_atonum("4294965252", &i));
+  EXPECT_EQ(-2044, i);
+
+  EXPECT_TRUE(FX_atonum("-4294965252", &i));
+  EXPECT_EQ(0, i);
+
+  EXPECT_TRUE(FX_atonum("+4294965252", &i));
+  EXPECT_EQ(0, i);
+
+  float f;
+  EXPECT_FALSE(FX_atonum("3.24", &f));
+  EXPECT_FLOAT_EQ(3.24f, f);
+}