The variables "[fReopenDebugLog](https://github.com/bitcoin/bitcoin/blob/fa24439ff3d8ab5b9efaf66ef4dae6713b88cb35/src/util.h#L53)" and "[fRequestShutdown](https://github.com/bitcoin/bitcoin/blob/fae78fa81802b5387054715c339f286ef436408e/src/init.cpp#L128)" should [use the data type "sig_atomic_t"](https://www.securecoding.cert.org/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers) (instead of "bool").

I reported this issue for [another evolving software](https://github.com/Electric-Coin-Company/zcash/issues/678) before.

/**
 * When we switch to C++11, this can be switched to variadic templates instead
 * of this macro-based construction (see tinyformat.h).
 */
#define MAKE_ERROR_AND_LOG_FUNC(n)                                        \
    /**   Print to debug.log if -debug=category switch is given OR category is NULL. */ \
    template<TINYFORMAT_ARGTYPES(n)>                                          \
    static inline int LogPrint(const char* category, const char* format, TINYFORMAT_VARARGS(n))  \
    {                                                                         \
        if(!LogAcceptCategory(category)) return 0;                            \
        return LogPrintStr(tfm::format(format, TINYFORMAT_PASSARGS(n))); \
    }                                                                         \
    /**   Log error and return false */                                        \
    template<TINYFORMAT_ARGTYPES(n)>                                          \
    static inline bool error(const char* format, TINYFORMAT_VARARGS(n))                     \
    {                                                                         \
        LogPrintStr("ERROR: " + tfm::format(format, TINYFORMAT_PASSARGS(n)) + "\n"); \
        return false;                                                         \
    }
TINYFORMAT_FOREACH_ARGNUM(MAKE_ERROR_AND_LOG_FUNC)
/**
 * Zero-arg versions of logging and error, these are not covered by
 * TINYFORMAT_FOREACH_ARGNUM
 */
static inline int LogPrint(const char* category, const char* format)
{
    if(!LogAcceptCategory(category)) return 0;
    return LogPrintStr(format);
}
static inline bool error(const char* format)