lp may overwrite constant data
If built with -xstrconst or with gcc without -fwritable-strings lp will overwrite constant strings when:
1. Checking the terminfo database (type_letter in _isterminfo)
2. In numerous places while forming argument error messages
3. ... in countless places other places as yet undiscovered (yech!)
This bug covers #1 and #2. People playing along at home may wish to grep cmd/lp for any string constant assigned to char* and considering each of them deeply suspicious (though I suspect even a pass that thorough will miss the more insidious bits of this pile).