converting char to unsigned long

[matrebatre]

When I try to convert a char to an unsigned long, the unsigned long is padded with 1's instead of 0's if the char is >=128. For example:

char c;
unsigned long ul;

c = 0x59;
ul = (unsigned long) c;
// now ul==0x00000059

c = 0x89;
ul = (unsigned long) c;
// now ul==0xffffff89 

But when I am using 'unsigned char', this does not happen. Aren't chars unsigned by default? Is this a bug?

[Bazzy]

A signed char can have as maximum value 127, 0x89 is 137 so it becomes -119.
-119ul is 0xffffff89ul

[matrebatre]

But I am using char, not signed char ...

[jsmith]

They are either signed by default or it is left to the compiler.