[hackers] [scc] Avoid accessing beyond end of string || Michael Forney

[git]

commit 1dfb93dc4b91b4c3e5186757965a42595e142b9a
Author:     Michael Forney <mfor...@mforney.org>
AuthorDate: Wed Feb 15 23:55:31 2017 -0800
Commit:     Roberto E. Vargas Caballero <k...@shike2.com>
CommitDate: Thu Feb 16 09:56:22 2017 +0100

    Avoid accessing beyond end of string
    
    When bp == lim, we should not dereference bp since it lies beyond the
    allocated memory.

diff --git a/cc1/code.c b/cc1/code.c
index c4ce697..01bf6ff 100644
--- a/cc1/code.c
+++ b/cc1/code.c
@@ -317,7 +317,7 @@ emitstring(Symbol *sym, Type *tp)
        lim = &sym->u.s[tp->n.elem];
        while (bp < lim) {
                s = bp;
-               while (isprint(*bp) && bp < lim)
+               while (bp < lim && isprint(*bp))
                        ++bp;
                if ((n = bp - s) > 1)
                        fprintf(outfp, "\t#\"%.*s\n", n, s);
@@ -329,7 +329,7 @@ emitstring(Symbol *sym, Type *tp)
                        fprintf(outfp,
                                "\t#%c%02X\n",
                                chartype->letter, (*bp++) & 0xFF);
-               } while (!isprint(*bp) && bp < lim);
+               } while (bp < lim && !isprint(*bp));
        }
 }