hush: fix multiple redirections of the same fd (bug 227)

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

3 files changed, 15 insertions, 2 deletions

diff --git a/shell/hush.c b/shell/hush.c
index cbec2dd71..5daca960c 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2646,7 +2646,9 @@ static int setup_redirects(struct command *prog, int squirrel[])
         for (redir = prog->redirects; redir; redir = redir->next) {
                 if (redir->rd_type == REDIRECT_HEREDOC2) {
                         /* rd_fd<<HERE case */
-                        if (squirrel && redir->rd_fd < 3) {
+                        if (squirrel && redir->rd_fd < 3
+                         && squirrel[redir->rd_fd] < 0
+                        ) {
                                 squirrel[redir->rd_fd] = dup(redir->rd_fd);
                         }
                         /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
@@ -2682,7 +2684,9 @@ static int setup_redirects(struct command *prog, int squirrel[])
                 }
 
                 if (openfd != redir->rd_fd) {
-                        if (squirrel && redir->rd_fd < 3) {
+                        if (squirrel && redir->rd_fd < 3
+                         && squirrel[redir->rd_fd] < 0
+                        ) {
                                 squirrel[redir->rd_fd] = dup(redir->rd_fd);
                         }
                         if (openfd == REDIRFD_CLOSE) {
diff --git a/shell/hush_test/hush-misc/redir6.right b/shell/hush_test/hush-misc/redir6.right
new file mode 100644
index 000000000..a97c4bdf1
--- /dev/null
+++ b/shell/hush_test/hush-misc/redir6.right
@@ -0,0 +1,4 @@
+Testing multiple redirections to same fd
+Hello
+Done1
+Done2
diff --git a/shell/hush_test/hush-misc/redir6.tests b/shell/hush_test/hush-misc/redir6.tests
new file mode 100755
index 000000000..c639ebb2d
--- /dev/null
+++ b/shell/hush_test/hush-misc/redir6.tests
@@ -0,0 +1,5 @@
+echo "Testing multiple redirections to same fd"
+# bug was making us lose fd #1 after this:
+echo Hello >/dev/null 1>&2
+echo Done1
+echo Done2 >&2