Use isRepresentableInteger here

Change-Id: I8ba202232fa42765a8b04113639fdac4b5724aa2
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/122941
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

1 files changed, 47 insertions, 53 deletions

diff --git a/sal/rtl/math.cxx b/sal/rtl/math.cxx
index f6a2b15a21d4..4d1111590089 100644
--- a/sal/rtl/math.cxx
+++ b/sal/rtl/math.cxx
@@ -335,71 +335,65 @@ void doubleToString(typename T::String ** pResult,
 
     // Use integer representation for integer values that fit into the
     // mantissa (1.((2^53)-1)) with a precision of 1 for highest accuracy.
-    const sal_Int64 kMaxInt = (static_cast< sal_Int64 >(1) << 53) - 1;
     if ((eFormat == rtl_math_StringFormat_Automatic ||
-         eFormat == rtl_math_StringFormat_F) && fValue <= static_cast< double >(kMaxInt))
+         eFormat == rtl_math_StringFormat_F) && isRepresentableInteger(fValue))
     {
         sal_Int64 nInt = static_cast< sal_Int64 >(fValue);
-        // Check the integer range again because double comparison may yield
-        // true within the precision range.
-        if (nInt <= kMaxInt && static_cast< double >(nInt) == fValue)
-        {
-            if (nDecPlaces == rtl_math_DecimalPlaces_Max)
-                nDecPlaces = 0;
-            else
-                nDecPlaces = ::std::clamp< sal_Int32 >(nDecPlaces, -15, 15);
+        if (nDecPlaces == rtl_math_DecimalPlaces_Max)
+            nDecPlaces = 0;
+        else
+            nDecPlaces = ::std::clamp< sal_Int32 >(nDecPlaces, -15, 15);
 
-            if (bEraseTrailingDecZeros && nDecPlaces > 0)
-                nDecPlaces = 0;
+        if (bEraseTrailingDecZeros && nDecPlaces > 0)
+            nDecPlaces = 0;
 
-            // Round before decimal position.
-            if (nDecPlaces < 0)
-            {
-                sal_Int64 nRounding = static_cast< sal_Int64 >(getN10Exp(-nDecPlaces - 1));
-                const sal_Int64 nTemp = (nInt / nRounding + 5) / 10;
-                nInt = nTemp * 10 * nRounding;
-            }
+        // Round before decimal position.
+        if (nDecPlaces < 0)
+        {
+            sal_Int64 nRounding = static_cast< sal_Int64 >(getN10Exp(-nDecPlaces - 1));
+            const sal_Int64 nTemp = (nInt / nRounding + 5) / 10;
+            nInt = nTemp * 10 * nRounding;
+        }
 
-            // Max 1 sign, 16 integer digits, 15 group separators, 1 decimal
-            // separator, 15 decimals digits.
-            typename T::Char aBuf[64];
-            typename T::Char* pEnd = aBuf + 40;
-            typename T::Char* pStart = pEnd;
+        // Max 1 sign, 16 integer digits, 15 group separators, 1 decimal
+        // separator, 15 decimals digits.
+        typename T::Char aBuf[64];
+        typename T::Char* pEnd = aBuf + 40;
+        typename T::Char* pStart = pEnd;
 
-            // Backward fill.
-            sal_Int32 nGrouping = cGroupSeparator && pGroups ? *pGroups : 0;
-            sal_Int32 nGroupDigits = 0;
-            do
+        // Backward fill.
+        sal_Int32 nGrouping = cGroupSeparator && pGroups ? *pGroups : 0;
+        sal_Int32 nGroupDigits = 0;
+        do
+        {
+            typename T::Char nDigit = nInt % 10;
+            nInt /= 10;
+            *--pStart = nDigit + '0';
+            if (nGrouping && nGrouping == ++nGroupDigits && nInt)
             {
-                typename T::Char nDigit = nInt % 10;
-                nInt /= 10;
-                *--pStart = nDigit + '0';
-                if (nGrouping && nGrouping == ++nGroupDigits && nInt)
-                {
-                    *--pStart = cGroupSeparator;
-                    if (*(pGroups + 1))
-                        nGrouping = *++pGroups;
-                    nGroupDigits = 0;
-                }
+                *--pStart = cGroupSeparator;
+                if (*(pGroups + 1))
+                    nGrouping = *++pGroups;
+                nGroupDigits = 0;
             }
-            while (nInt);
-            if (bSign)
-                *--pStart = '-';
+        }
+        while (nInt);
+        if (bSign)
+            *--pStart = '-';
 
-            // Append decimals.
-            if (nDecPlaces > 0)
-            {
-                *pEnd++ = cDecSeparator;
-                pEnd = std::fill_n(pEnd, nDecPlaces, '0');
-            }
+        // Append decimals.
+        if (nDecPlaces > 0)
+        {
+            *pEnd++ = cDecSeparator;
+            pEnd = std::fill_n(pEnd, nDecPlaces, '0');
+        }
 
-            if (!pResultCapacity)
-                T::createString(pResult, pStart, pEnd - pStart);
-            else
-                T::appendChars(pResult, pResultCapacity, &nResultOffset, pStart, pEnd - pStart);
+        if (!pResultCapacity)
+            T::createString(pResult, pStart, pEnd - pStart);
+        else
+            T::appendChars(pResult, pResultCapacity, &nResultOffset, pStart, pEnd - pStart);
 
-            return;
-        }
+        return;
     }
 
     // find the exponent