The following sequence of commands: set GS_OPTIONS=-dMéditéranéen gswin32c leads to: Debug Assertion failed! File: isctype.c [this one is from the C RunTime, not from GS] Expression: (unsigned)(c + 1) <= 256 Ghostscript compiled on Windows using Visual Studio .NET 2003. Cause: VS treats the "char" type as signed by default. This means that when extended characters are promoted to ints, the values are negative in the range -128 to -1. These values (except -1 which conflicts with EOF) are not valid for the "is*()" family of functions. GS does exhibit this problem while parsing the GS_OPTIONS. Not sure if this can ever happen with command line arguments or @files. This does not seem to be a regression, the SVN history shows the affected part as being from revision 2 (but it is older for sure).
Created attachment 7678 [details] Suggested patch. Bug 692347: "Assertion failed! (unsigned)(c + 1) <= 256" with extended chars in GS_OPTIONS. In some circumstances, characters from the arguments are passed to "isspace()", which expects an int argument in the rage 0..255 or the value EOF. In the char type is signed, character values of 128 and larger are considered negative, and promoted to negative integers outside the range accepted by "isspace()".
This patch has been committed by Ray on 2011-07-17 as a rev. 44a2fd0bb1e2dd12e9ba475da0bdbb93081325d5