master 188dc2e: Fix bug in recent byte-code checking hoist

[Paul Eggert]

branch: master
commit 188dc2e5a3cb2de69ec14715ba288ab1e30da6eb
Author: Paul Eggert <eggert@cs.ucla.edu>
Commit: Paul Eggert <eggert@cs.ucla.edu>

    Fix bug in recent byte-code checking hoist
    
    Problem reported by Daniel Colascione (Bug#41680).
    * src/lread.c (read1): Check that AREF (tmp, COMPILED_BYTECODE)
    is a string before subjecting it to STRING_MULTIBYTE.
    Be more consistent about using AREF in the neighborhood,
    to help prevent this sort of problem from recurring.
---
 src/lread.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/lread.c b/src/lread.c
index 29dedda..8064bf4 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2966,17 +2966,18 @@ read1 (Lisp_Object readcharfun, int *pch, bool 
first_in_list)
          struct Lisp_Vector *vec;
          tmp = read_vector (readcharfun, 1);
          vec = XVECTOR (tmp);
-         if (! (COMPILED_STACK_DEPTH < vec->header.size
-                && (FIXNUMP (vec->contents[COMPILED_ARGLIST])
-                    || CONSP (vec->contents[COMPILED_ARGLIST])
-                    || NILP (vec->contents[COMPILED_ARGLIST]))
-                && ((STRINGP (vec->contents[COMPILED_BYTECODE])
-                     && VECTORP (vec->contents[COMPILED_CONSTANTS]))
-                    || CONSP (vec->contents[COMPILED_BYTECODE]))
-                && FIXNATP (vec->contents[COMPILED_STACK_DEPTH])))
+         if (! (COMPILED_STACK_DEPTH < ASIZE (tmp)
+                && (FIXNUMP (AREF (tmp, COMPILED_ARGLIST))
+                    || CONSP (AREF (tmp, COMPILED_ARGLIST))
+                    || NILP (AREF (tmp, COMPILED_ARGLIST)))
+                && ((STRINGP (AREF (tmp, COMPILED_BYTECODE))
+                     && VECTORP (AREF (tmp, COMPILED_CONSTANTS)))
+                    || CONSP (AREF (tmp, COMPILED_BYTECODE)))
+                && FIXNATP (AREF (tmp, COMPILED_STACK_DEPTH))))
            invalid_syntax ("Invalid byte-code object");
 
-         if (STRING_MULTIBYTE (AREF (tmp, COMPILED_BYTECODE)))
+         if (STRINGP (AREF (tmp, COMPILED_BYTECODE))
+             && STRING_MULTIBYTE (AREF (tmp, COMPILED_BYTECODE)))
            {
              /* BYTESTR must have been produced by Emacs 20.2 or earlier
                 because it produced a raw 8-bit string for byte-code and
@@ -2987,7 +2988,7 @@ read1 (Lisp_Object readcharfun, int *pch, bool 
first_in_list)
                    Fstring_as_unibyte (AREF (tmp, COMPILED_BYTECODE)));
            }
 
-         if (COMPILED_DOC_STRING < vec->header.size
+         if (COMPILED_DOC_STRING < ASIZE (tmp)
              && EQ (AREF (tmp, COMPILED_DOC_STRING), make_fixnum (0)))
            {
              /* read_list found a docstring like '(#$ . 5521)' and treated it