From: Andy Heninger <andy.heninger@gmail.com>
Date: Mon, 19 Feb 2018 03:13:08 +0000 (+0000)
Subject: ICU-13550 decNumber int overflow, switch to unsigned to avoid undefined behavior.
X-Git-Tag: release-61-rc~71
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1d9c8ee33d045b1302e8dbe462aa05557a447d45;p=icu

ICU-13550 decNumber int overflow, switch to unsigned to avoid undefined behavior.

X-SVN-Rev: 40950
---

diff --git a/icu4c/source/i18n/decNumber.cpp b/icu4c/source/i18n/decNumber.cpp
index 149062e0921..cee2f8e9498 100644
--- a/icu4c/source/i18n/decNumber.cpp
+++ b/icu4c/source/i18n/decNumber.cpp
@@ -627,10 +627,12 @@ U_CAPI decNumber * U_EXPORT2 uprv_decNumberFromString(decNumber *dn, const char
 
       for (; *c=='0' && *(c+1)!='\0';) c++;  /* strip insignificant zeros  */
       firstexp=c;                            /* save exponent digit place  */
+      uInt uexponent = 0;   /* Avoid undefined behavior on signed int overflow */
       for (; ;c++) {
         if (*c<'0' || *c>'9') break;         /* not a digit  */
-        exponent=X10(exponent)+(Int)*c-(Int)'0';
+        uexponent=X10(uexponent)+(uInt)*c-(uInt)'0';
         } /* c  */
+      exponent = (Int)uexponent;
       /* if not now on a '\0', *c must not be a digit  */
       if (*c!='\0') break;