[asterisk-bugs] [JIRA] (ASTERISK-24619) Gcc 4.10 fixes in r413589 (1.8) wrongly casts char to unsigned int

[Walter Doekes (JIRA)]

Walter Doekes created ASTERISK-24619:
----------------------------------------

             Summary: Gcc 4.10 fixes in r413589 (1.8) wrongly casts char to unsigned int
                 Key: ASTERISK-24619
                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-24619
             Project: Asterisk
          Issue Type: Bug
      Security Level: None
    Affects Versions: 1.8.32.1, SVN
            Reporter: Walter Doekes


Example:

{noformat}
int main() { const char *abc = "åäö"; return (((unsigned) abc[3]) >> 24) == 0 ? 0 : 1; }
{noformat}
yields 1

Or, more visibly:
{noformat}
#include <stdio.h>
int main() {
	const char *abc = "åäö";
	printf("bad:  %02X\n", (unsigned)*abc);
	printf("good: %02hhX\n", (unsigned char)*abc);
	return 0;
}
{noformat}

yields:
{noformat}
$ ./a.out 
bad:  FFFFFFC3
good: C3
{noformat}

Unfortunately, the changes in r413589 introduce just that.
E.g.:
{noformat}
$ svn diff -c 413586 > tmp.diff
$ grep '^-.*(unsigned char)' tmp.diff -A1
-			sprintf(digest + (idx << 1), "%2.2x", (unsigned char) key[idx]); \
+			sprintf(digest + (idx << 1), "%2.2x", (unsigned) key[idx]); \
--
-		sprintf(&addrmac[i], "%.2x", (unsigned char) buf[tmp]);
+		sprintf(&addrmac[i], "%.2x", (unsigned) buf[tmp]);
--
-		sprintf(p, "%02X ", (unsigned char)buf[f]);
+		sprintf(p, "%02X ", (unsigned)buf[f]);
--
-			out += sprintf(out, "%%%02X", (unsigned char) *ptr);
+			out += sprintf(out, "%%%02X", (unsigned) *ptr);
{noformat}

That's wrong, the compiler warnings should have been fixed using the hh (char) modifier: {{%02hhX}}

Issue was reported by stefan27 via IRC.



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