hush: handle backslash-newline in heredoc terminators

function                                             old     new   delta
fetch_heredocs                                       479     527     +48

(ash fails this test)

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

5 files changed, 28 insertions, 2 deletions

diff --git a/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.right b/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.right
new file mode 100644
index 000000000..3d79316d7
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.right
@@ -0,0 +1 @@
+Ok1
diff --git a/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.tests b/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.tests
new file mode 100755
index 000000000..1d2a26504
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc_bkslash_newline2.tests
@@ -0,0 +1,4 @@
+cat <<EOF
+Ok1
+EO\
+F
diff --git a/shell/hush.c b/shell/hush.c
index 75bce337a..c26484b49 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4250,6 +4250,7 @@ static char *fetch_till_str(o_string *as_string,
                 if (ch == '\n' || ch == EOF) {
  check_heredoc_end:
                         if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
+                                /* End-of-line, and not a line continuation */
                                 if (strcmp(heredoc.data + past_EOL, word) == 0) {
                                         heredoc.data[past_EOL] = '\0';
                                         debug_printf_heredoc("parsed '%s' heredoc '%s'\n", word, heredoc.data);
@@ -4275,17 +4276,32 @@ static char *fetch_till_str(o_string *as_string,
                                         if (ch == '\n')
                                                 goto check_heredoc_end;
                                 }
+                        } else {
+                                /* Backslash-line continuation in an unquoted
+                                 * heredoc. This does not need special handling
+                                 * for heredoc body (unquoted heredocs are
+                                 * expanded on "execution" and that would take
+                                 * care of this case too), but not the case
+                                 * of line continuation *in terminator*:
+                                 *  cat <<EOF
+                                 *  Ok1
+                                 *  EO\
+                                 *  F
+                                 */
+                                heredoc.data[--heredoc.length] = '\0';
+                                prev = 0; /* not '\' */
+                                continue;
                         }
                 }
                 if (ch == EOF) {
                         o_free(&heredoc);
-                        return NULL;
+                        return NULL; /* error */
                 }
                 o_addchr(&heredoc, ch);
                 nommu_addchr(as_string, ch);
                 if (prev == '\\' && ch == '\\')
                         /* Correctly handle foo\\<eol> (not a line cont.) */
-                        prev = 0; /* not \ */
+                        prev = 0; /* not '\' */
                 else
                         prev = ch;
         }
diff --git a/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.right b/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.right
new file mode 100644
index 000000000..3d79316d7
--- /dev/null
+++ b/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.right
@@ -0,0 +1 @@
+Ok1
diff --git a/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.tests b/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.tests
new file mode 100755
index 000000000..1d2a26504
--- /dev/null
+++ b/shell/hush_test/hush-heredoc/heredoc_bkslash_newline2.tests
@@ -0,0 +1,4 @@
+cat <<EOF
+Ok1
+EO\
+F