3 files changed, 92 insertions, 5 deletions

diff --git a/shell/hush.c b/shell/hush.c
index ef46372de..e8aef2d7e 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3162,17 +3162,20 @@ static int redirect_opt_num(o_string *o)
 static char *fetch_till_str(o_string *as_string,
                 struct in_str *input,
                 const char *word,
-                int skip_tabs)
+                int heredoc_flags)
 {
         o_string heredoc = NULL_O_STRING;
         int past_EOL = 0;
+        int prev = 0; /* not \ */
         int ch;
 
         goto jump_in;
         while (1) {
                 ch = i_getch(input);
                 nommu_addchr(as_string, ch);
-                if (ch == '\n') {
+                if (ch == '\n'
+                 && ((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);
@@ -3185,7 +3188,7 @@ static char *fetch_till_str(o_string *as_string,
                                 do {
                                         ch = i_getch(input);
                                         nommu_addchr(as_string, ch);
-                                } while (skip_tabs && ch == '\t');
+                                } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
                         } while (ch == '\n');
                 }
                 if (ch == EOF) {
@@ -3194,6 +3197,7 @@ static char *fetch_till_str(o_string *as_string,
                 }
                 o_addchr(&heredoc, ch);
                 nommu_addchr(as_string, ch);
+                prev = ch;
         }
 }
 
@@ -3223,7 +3227,7 @@ static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_
                                         redir->rd_type = REDIRECT_HEREDOC2;
                                         /* redir->rd_dup is (ab)used to indicate <<- */
                                         p = fetch_till_str(&ctx->as_string, input,
-                                                redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
+                                                        redir->rd_filename, redir->rd_dup);
                                         if (!p) {
                                                 syntax_error("unexpected EOF in here document");
                                                 return 1;
@@ -3778,8 +3782,9 @@ static int parse_stream_dquoted(o_string *as_string,
                  * only when followed by one of the following characters:
                  * $, `, ", \, or <newline>.  A double quote may be quoted
                  * within double quotes by preceding it with a backslash."
+                 * NB: in (unquoted) heredoc, above does not apply to ".
                  */
-                if (strchr("$`\"\\\n", next) != NULL) {
+                if (next == dquote_end || strchr("$`\\\n", next) != NULL) {
                         ch = i_getch(input);
                         if (ch != '\n') {
                                 o_addqchr(dest, ch);
@@ -4412,6 +4417,7 @@ static char *expand_pseudo_dquoted(const char *str)
         o_string dest = NULL_O_STRING;
 
         if (!strchr(str, '$')
+         && !strchr(str, '\\')
 #if ENABLE_HUSH_TICK
          && !strchr(str, '`')
 #endif
diff --git a/shell/hush_test/hush-misc/heredoc_backslash1.right b/shell/hush_test/hush-misc/heredoc_backslash1.right
new file mode 100644
index 000000000..234c0172f
--- /dev/null
+++ b/shell/hush_test/hush-misc/heredoc_backslash1.right
@@ -0,0 +1,27 @@
+Quoted heredoc:
+a\
+        b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+        -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+
+Unquoted heredoc:
+a       b
+ 123456 -qwerty-\t-\-\"-\'-`-\--\z-\*-\?-
+        -qwerty-\t-\-\"-\'-`-\--\z-\*-\?-
+cEOF2
+
+Quoted -heredoc:
+a\
+b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+-$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+
+Unquoted -heredoc:
+a       b
+ 123456 -qwerty-\t-\-\"-\'-`-\--\z-\*-\?-
+-qwerty-\t-\-\"-\'-`-\--\z-\*-\?-
+cEOF4
+
+Done: 0
diff --git a/shell/hush_test/hush-misc/heredoc_backslash1.tests b/shell/hush_test/hush-misc/heredoc_backslash1.tests
new file mode 100755
index 000000000..b70467df8
--- /dev/null
+++ b/shell/hush_test/hush-misc/heredoc_backslash1.tests
@@ -0,0 +1,54 @@
+# Test for correct handling of backslashes.
+# Note that some lines in each heredoc start with a tab.
+
+a=qwerty
+
+echo Quoted heredoc:
+cat <<"EOF1"
+a\
+        b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+        -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+EOF1
+echo
+
+echo Unquoted heredoc:
+cat <<EOF2
+a\
+        b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+        -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+EOF2
+EOF2
+echo
+
+echo Quoted -heredoc:
+cat <<-"EOF3"
+a\
+        b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+        -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+        EOF3
+# In -heredoc case the marker is detected even if it is indented.
+echo
+
+echo Unquoted -heredoc:
+cat <<-EOF4
+a\
+        b
+ 123456 -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+        -$a-\t-\\-\"-\'-\`-\--\z-\*-\?-
+c\
+EOF4
+        EOF4
+# The marker is not detected if preceding line ends in backslash.
+# TODO: marker should be detected even if it is split by line continuation:
+# EOF\
+# 4
+# but currently hush doesn't do it. (Tab before "4" is not allowed, though.)
+echo
+
+echo "Done: $?"