hush: fix handling of empty heredoc EOF marker

function                                             old     new   delta
parse_stream                                        2609    2634     +25

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

5 files changed, 63 insertions, 17 deletions

diff --git a/shell/ash_test/ash-heredoc/heredoc_empty2.right b/shell/ash_test/ash-heredoc/heredoc_empty2.right
new file mode 100644
index 000000000..e32c6ea58
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc_empty2.right
@@ -0,0 +1,4 @@
+OK1
+Ok:0
+OK2
+Ok:0
diff --git a/shell/ash_test/ash-heredoc/heredoc_empty2.tests b/shell/ash_test/ash-heredoc/heredoc_empty2.tests
new file mode 100755
index 000000000..20fc35fe9
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc_empty2.tests
@@ -0,0 +1,14 @@
+unset a
+
+# Heredoc with empty delimiter
+cat <<- ""
+        OK1
+
+echo Ok:$?
+
+# Heredoc with empty delimiter
+cat <<- ""
+        OK2
+        
+
+echo Ok:$?
diff --git a/shell/hush.c b/shell/hush.c
index d0225edb9..0fae809b3 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4001,24 +4001,34 @@ static char *fetch_till_str(o_string *as_string,
                 ch = i_getch(input);
                 if (ch != EOF)
                         nommu_addchr(as_string, ch);
-                if ((ch == '\n' || ch == EOF)
-                 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
-                ) {
-                        if (strcmp(heredoc.data + past_EOL, word) == 0) {
-                                heredoc.data[past_EOL] = '\0';
-                                debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
-                                return heredoc.data;
-                        }
-                        while (ch == '\n') {
-                                o_addchr(&heredoc, ch);
-                                prev = ch;
+                if (ch == '\n' || ch == EOF) {
+ check_heredoc_end:
+                        if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
+                                if (strcmp(heredoc.data + past_EOL, word) == 0) {
+                                        heredoc.data[past_EOL] = '\0';
+                                        debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
+                                        return heredoc.data;
+                                }
+                                if (ch == '\n') {
+                                        /* This is a new line.
+                                         * Remember position and backslash-escaping status.
+                                         */
+                                        o_addchr(&heredoc, ch);
+                                        prev = ch;
  jump_in:
-                                past_EOL = heredoc.length;
-                                do {
-                                        ch = i_getch(input);
-                                        if (ch != EOF)
-                                                nommu_addchr(as_string, ch);
-                                } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
+                                        past_EOL = heredoc.length;
+                                        /* Get 1st char of next line, possibly skipping leading tabs */
+                                        do {
+                                                ch = i_getch(input);
+                                                if (ch != EOF)
+                                                        nommu_addchr(as_string, ch);
+                                        } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
+                                        /* If this immediately ended the line,
+                                         * go back to end-of-line checks.
+                                         */
+                                        if (ch == '\n')
+                                                goto check_heredoc_end;
+                                }
                         }
                 }
                 if (ch == EOF) {
diff --git a/shell/hush_test/hush-heredoc/heredoc_empty2.right b/shell/hush_test/hush-heredoc/heredoc_empty2.right
new file mode 100644
index 000000000..e32c6ea58
--- /dev/null
+++ b/shell/hush_test/hush-heredoc/heredoc_empty2.right
@@ -0,0 +1,4 @@
+OK1
+Ok:0
+OK2
+Ok:0
diff --git a/shell/hush_test/hush-heredoc/heredoc_empty2.tests b/shell/hush_test/hush-heredoc/heredoc_empty2.tests
new file mode 100755
index 000000000..20fc35fe9
--- /dev/null
+++ b/shell/hush_test/hush-heredoc/heredoc_empty2.tests
@@ -0,0 +1,14 @@
+unset a
+
+# Heredoc with empty delimiter
+cat <<- ""
+        OK1
+
+echo Ok:$?
+
+# Heredoc with empty delimiter
+cat <<- ""
+        OK2
+        
+
+echo Ok:$?