BASE: Correct usage of strtol().

- endptr needs not be initialised before calling strtol(), it is always set by strtol().
- endptr is never a null pointer after calling strtol().
- There is no need to rely on strtol() setting EINVAL (which is not guaranteed).
  Testing whether strtol() parsed till the end of the string is sufficient (it is guaranteed that the string is not empty at this point).
- It is sufficient to just test for ERANGE without inspecting the return value, because a successful call to strtol() does not change errno.

Signed-off-by: Alyssa Milburn <fuzzie@fuzzie.org>

base/commandLine.cpp

@@ -26,7 +26,6 @@
 #define FORBIDDEN_SYMBOL_EXCEPTION_exit
 
 #include <errno.h>
-#include <limits.h>
 
 #include "engines/metaengine.h"
 #include "base/commandLine.h"
@@ -269,10 +268,10 @@ void registerDefaults() {
 // Use this for options which have a required integer value
 #define DO_OPTION_INT(shortCmd, longCmd) \
 	DO_OPTION(shortCmd, longCmd) \
-	char *endptr = 0; \
+	char *endptr; \
 	errno = 0; \
-	long int retval = strtol(option, &endptr, 0); \
-	if (endptr == NULL || *endptr != 0 || (errno != 0 && retval == 0) || (errno == ERANGE && (retval == LONG_MAX || retval == LONG_MIN))) \
+	strtol(option, &endptr, 0); \
+	if (*endptr != '\0' || errno == ERANGE) \
 		usage("--%s: Invalid number '%s'", longCmd, option);
 
 // Use this for boolean options; this distinguishes between "-x" and "-X",