hush: fix backslash and terminator handling in <<[-]["]heredoc["]

function                                             old     new   delta
parse_stream                                        2339    2395     +56
expand_pseudo_dquoted                                104     118     +14
parse_stream_dquoted                                 296     300      +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 74/0)               Total: 74 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

1 files changed, 11 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