Related: tdf#136272 accept 1.79769313486232e+308 as DBL_MAX

This does not solve writing the badly rounded value, which still
has to be fixed, but at least be able to read/convert it back as
double max value.

This is not even used in the bug scenario because the "fake"
condition in that number format is discarded anyway because it was
only written to satisfy ODF, but it helps in case a
1.7976931348623157e+308 value was entered/used on purpose.

Change-Id: I413dd93d5a3c4df609fd42a3133d6d82c34afff0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/106586
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins
(cherry picked from commit ee2cc952eeb5385ee37485c822d7ad7abd8fb989)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/106526

1 files changed, 20 insertions, 1 deletions

diff --git a/sal/rtl/math.cxx b/sal/rtl/math.cxx
index af3e52f2bf9d..c58c646bbc2e 100644
--- a/sal/rtl/math.cxx
+++ b/sal/rtl/math.cxx
@@ -976,7 +976,26 @@ double stringToDouble(CharT const * pBegin, CharT const * pEnd,
             errno = 0;
             fVal = strtod_nolocale(buf, &pCharParseEnd);
             if (errno == ERANGE)
-                eStatus = rtl_math_ConversionStatus_OutOfRange;
+            {
+                // Check for the dreaded rounded to 15 digits max value
+                // 1.79769313486232e+308 for 1.7976931348623157e+308 we wrote
+                // everywhere, accept with or without plus sign in exponent.
+                const char* b = buf;
+                if (b[0] == '-')
+                    ++b;
+                if (((pCharParseEnd - b == 21) || (pCharParseEnd - b == 20))
+                        && !strncmp( b, "1.79769313486232", 16)
+                        && (b[16] == 'e' || b[16] == 'E')
+                        && (((pCharParseEnd - b == 21) && !strncmp( b+17, "+308", 4))
+                         || ((pCharParseEnd - b == 20) && !strncmp( b+17, "308", 3))))
+                {
+                    fVal = (buf < b) ? -DBL_MAX : DBL_MAX;
+                }
+                else
+                {
+                    eStatus = rtl_math_ConversionStatus_OutOfRange;
+                }
+            }
             p = bufmap[pCharParseEnd - buf];
             bSign = false;
         }