ash: parser: Fix incorrect eating of backslash newlines

Keeping up with upstream (in our case, 'before patch' code is not buggy).
Upstream commit:

    Date: Fri, 11 May 2018 23:41:25 +0800
    parser: Fix incorrect eating of backslash newlines

    With the introduction of synstack->syntax, a number of references
    to the syntax variable was missed during the conversion.  This
    causes backslash newlines to be incorrectly removed in single
    quote context.

    This patch also combines these calls into a new helper function
    pgetc_top.

    Fixes: ab1cecb40478 ("parser: Add syntax stack for recursive...")
    Reported-by: Leah Neukirchen <leah@vuxu.org>
    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/ash.c b/shell/ash.c
index c177ac038982cee244d5f2aa208ba236859467bd..a300061a24288df9a4f15eae9f656df39ceb7089 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -10829,6 +10829,12 @@ struct synstack {
        struct synstack *next;
 };
 
+static int
+pgetc_top(struct synstack *stack)
+{
+       return stack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
+}
+
 static void
 synstack_push(struct synstack **stack, struct synstack *next, int syntax)
 {
@@ -12194,7 +12200,7 @@ readtoken1(int c, int syntax, char *eofmark, int striptabs)
                        }
                        USTPUTC(c, out);
                        nlprompt();
-                       c = synstack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
+                       c = pgetc_top(synstack);
                        goto loop;              /* continue outer loop */
                case CWORD:
                        USTPUTC(c, out);
@@ -12345,7 +12351,7 @@ readtoken1(int c, int syntax, char *eofmark, int striptabs)
                        IF_ASH_ALIAS(if (c != PEOA))
                                USTPUTC(c, out);
                }
-               c = synstack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
+               c = pgetc_top(synstack);
        } /* for (;;) */
  endword: