ash: fix signed char expansion bug

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 21 insertions, 9 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 91bcccb9d..8d8cc466b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -3113,7 +3113,18 @@ static const uint8_t syntax_index_table[] ALIGN1 = {
 # endif
 };
 
+#if 1
 # define SIT(c, syntax) ((S_I_T[syntax_index_table[c]] >> ((syntax)*4)) & 0xf)
+#else /* debug version, caught one signed char bug */
+# define SIT(c, syntax) \
+        ({ \
+                if ((c) < 0 || (c) > (PEOF + ENABLE_ASH_ALIAS)) \
+                        bb_error_msg_and_die("line:%d c:%d", __LINE__, (c)); \
+                if ((syntax) < 0 || (syntax) > (2 + ENABLE_SH_MATH_SUPPORT)) \
+                        bb_error_msg_and_die("line:%d c:%d", __LINE__, (c)); \
+                ((S_I_T[syntax_index_table[c]] >> ((syntax)*4)) & 0xf); \
+        })
+#endif
 
 #endif  /* !USE_SIT_FUNCTION */
 
@@ -5869,14 +5880,15 @@ memtodest(const char *p, size_t len, int syntax, int quotes)
         do {
                 unsigned char c = *p++;
                 if (c) {
-                        int n = SIT(c, syntax);
-                        if ((quotes & QUOTES_ESC)
-                         && ((n == CCTL)
-                            ||  (((quotes & EXP_FULL) || syntax != BASESYNTAX)
-                                && n == CBACK)
-                                )
-                        ) {
-                                USTPUTC(CTLESC, q);
+                        if (quotes & QUOTES_ESC) {
+                                int n = SIT(c, syntax);
+                                if (n == CCTL
+                                 || (((quotes & EXP_FULL) || syntax != BASESYNTAX)
+                                     && n == CBACK
+                                    )
+                                ) {
+                                        USTPUTC(CTLESC, q);
+                                }
                         }
                 } else if (!(quotes & QUOTES_KEEPNUL))
                         continue;
@@ -10051,7 +10063,7 @@ pgetc(void)
                 return g_parsefile->lastc[--g_parsefile->unget];
 
         if (--g_parsefile->left_in_line >= 0)
-                c = (signed char)*g_parsefile->next_to_pgetc++;
+                c = (unsigned char)*g_parsefile->next_to_pgetc++;
         else
                 c = preadbuffer();