fix stack overflow in php_intlog10abs()

bug uncovered by LLVM/clang's new -fbounds-checking switch
this patch fixes a crash in ext/standard/tests/math/round_large_exp.phpt

diff --git a/ext/standard/math.c b/ext/standard/math.c
index 21c730c928560478c7c95ad3989b8e60a4130c8a..749c77c75c7c37ae2201182fea966119bd83642a 100644 (file)
--- a/ext/standard/math.c
+++ b/ext/standard/math.c
@@ -37,7 +37,7 @@ static inline int php_intlog10abs(double value) {
        int result;
        value = fabs(value);
 
-       if (value < 1e-8 || value > 1e23) {
+       if (value < 1e-8 || value > 1e22) {
                result = (int)floor(log10(value));
        } else {
                static const double values[] = {
@@ -46,7 +46,7 @@ static inline int php_intlog10abs(double value) {
                        1e8,  1e9,  1e10, 1e11, 1e12, 1e13, 1e14, 1e15,
                        1e16, 1e17, 1e18, 1e19, 1e20, 1e21, 1e22};
                /* Do a binary search with 5 steps */
-               result = 16;
+               result = 15;
                if (value < values[result]) {
                        result -= 8;
                } else {