Re: [issue] XEmacs often crashes when "VI emulation" is activated. (RHEL4)

Daniel Novotny writes: > I am now solving a bug in RHEL4 > (https://bugzilla.redhat.com/show_bug.cgi?id=249668), but I got to > very strange behavior while debugging it > > in the "bytecode.c" file xemacs abort()s in the function > execute_rare_opcode(), because it somehow got another opcode than > the ones listed in the switch: There is a known type of bug in the bytecode interpreter where bytecode interpreter's stack gets corrupted. This kind of bug is due to a failure of one of the bytecode internal functions to save enough stack space. That bug has this kind of signature. > inside the function execute_rare_opcode() the "opcode" parameter > seems to be 0, however when I go one stack frame up, What function is in the parent frame?

> it shows that the REGISTER variable "opcode", which should get > passed to the function, is 5590 and not 0, This is already bad. When opcode gets passed to execute_rare_opcode, it's supposed to be an enum; 5590 is out of range (> 255) and neither 0 nor 5590 % 256 are valid members of the enum. If it's a compiler issue, it may have to do with misuse of register variables. You could try compiling without the register declaration.