Re: Segfault because metafy() writes to a const char

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Feb 18,  4:30pm, Theo Buehler wrote:
} Subject: Segfault because metafy() writes to a const char
}
} The following patch fixes this problem for me, however, it effectively
} undoes a patch discussed in this thread:
} 
} 
} http://www.zsh.org/mla/workers/2013/msg01089.html
} 
} and, especially here:
} 
} http://www.zsh.org/mla/workers/2013/msg01091.html

If you look at the followup to that message:

http://www.zsh.org/mla/workers/2013/msg01092.html

("we need to change the caller")  The fix should be this:


diff --git a/Src/module.c b/Src/module.c
index 7dd4701..368254c 100644
--- a/Src/module.c
+++ b/Src/module.c
@@ -1601,7 +1601,7 @@ do_load_module(char const *name, int silent)
 #ifdef HAVE_DLERROR
 	char *errstr = dlerror();
 	zwarn("failed to load module `%s': %s", name,
-	      errstr ? metafy(errstr, -1, META_USEHEAP) : "empty module path");
+	      errstr ? metafy(errstr, -1, META_HEAPDUP) : "empty module path");
 #else
 	zwarn("failed to load module: %s", name);
 #endif

(Could probably even use META_STATIC there, the dlerror string is not very
likely to be too long for PATH_MAX.)

It still seems as though we should be able to avoid nul-terminating a
string that's already nul-terminated without changing the call sign of
metafy().