printf: fix printf "%u\n" +18446744073709551614

function                                             old     new   delta
conv_strtoll                                          19      32     +13
conv_strtoull                                         49      61     +12
bb_strtoll                                            89      84      -5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 25/-5)              Total: 20 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

coreutils/printf.c

@@ -95,6 +95,12 @@ static int multiconvert(const char *arg, void *result, converter convert)
 
 static void FAST_FUNC conv_strtoull(const char *arg, void *result)
 {
+	/* Allow leading '+' - bb_strtoull() by itself does not allow it,
+	 * and probably shouldn't (other callers might require purely numeric
+	 * inputs to be allowed.
+	 */
+	if (arg[0] == '+')
+		arg++;
 	*(unsigned long long*)result = bb_strtoull(arg, NULL, 0);
 	/* both coreutils 6.10 and bash 3.2:
 	 * $ printf '%x\n' -2
@@ -107,6 +113,8 @@ static void FAST_FUNC conv_strtoull(const char *arg, void *result)
 }
 static void FAST_FUNC conv_strtoll(const char *arg, void *result)
 {
+	if (arg[0] == '+')
+		arg++;
 	*(long long*)result = bb_strtoll(arg, NULL, 0);
 }
 static void FAST_FUNC conv_strtod(const char *arg, void *result)

libbb/bb_strtonum.c

@@ -81,7 +81,7 @@ long long FAST_FUNC bb_strtoll(const char *arg, char **endp, int base)
 	/* Check for the weird "feature":
 	 * a "-" string is apparently a valid "number" for strto[u]l[l]!
 	 * It returns zero and errno is 0! :( */
-	first = (arg[0] != '-' && arg[0] != '+' ? arg[0] : arg[1]);
+	first = (arg[0] != '-' ? arg[0] : arg[1]);
 	if (!isalnum(first)) return ret_ERANGE();
 
 	errno = 0;