On Fri, Jul 01, 2022 at 07:03:18PM +0200, Roland Illig wrote: > The macro 'isspace' must only be called with an integer representable as > an 'unsigned char', or with the value of the macro EOF. > > On platforms where plain 'char' is a signed integer type, any character > whose value is negative invokes undefined behavior (except for the one > character that by coincidence has the same value as the macro EOF). > > To fix this, write '!isspace((unsigned char)*str)' instead. > > I have no idea how to trigger this part of the code but for someone who > knows this part of Git, it should be easy. Depending on the platform, > this kind of error may be silently ignored or crash the program, as > always with undefined behavior. We don't use the system isspace(), but instead our own macro wrappers in git-compat-util.h. They do the cast to unsigned char themselves. I won't be surprised if re-defining a system name as a macro is also technically undefined behavior, but I don't think we've found a system that has a problem with it in the past 17 years. :) -Peff
