}
}
+int toint(unsigned u)
+{
+ /*
+ * Convert an unsigned to an int, without running into the
+ * undefined behaviour which happens by the strict C standard if
+ * the value overflows. You'd hope that sensible compilers would
+ * do the sensible thing in response to a cast, but actually I
+ * don't trust modern compilers not to do silly things like
+ * assuming that _obviously_ you wouldn't have caused an overflow
+ * and so they can elide an 'if (i < 0)' test immediately after
+ * the cast.
+ *
+ * Sensible compilers ought of course to optimise this entire
+ * function into 'just return the input value'!
+ */
+ if (u <= (unsigned)INT_MAX)
+ return (int)u;
+ else if (u >= (unsigned)INT_MIN) /* wrap in cast _to_ unsigned is OK */
+ return INT_MIN + (int)(u - (unsigned)INT_MIN);
+ else
+ return INT_MIN; /* fallback; should never occur on binary machines */
+}
+
/*
* Do an sprintf(), but into a custom-allocated buffer.
*