hush: fix 'eval ""' handling

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-misc/eval2.right b/shell/ash_test/ash-misc/eval2.right
new file mode 100644
index 0000000..a7ce6cc
--- /dev/null
+++ b/shell/ash_test/ash-misc/eval2.right
@@ -0,0 +1,3 @@
+Zero:0
+Zero:0
+Zero:0
diff --git a/shell/ash_test/ash-misc/eval2.tests b/shell/ash_test/ash-misc/eval2.tests
new file mode 100755
index 0000000..6bfb87a
--- /dev/null
+++ b/shell/ash_test/ash-misc/eval2.tests
@@ -0,0 +1,4 @@
+false; eval; echo Zero:$?
+false; eval ""; echo Zero:$?
+false; eval "
+"; echo Zero:$?
diff --git a/shell/hush.c b/shell/hush.c
index 5698de6..d7d152c 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -5679,7 +5679,7 @@
 			n++;
 		}
 	}
-	overlapping_strcpy((char*)list, list[0]);
+	overlapping_strcpy((char*)list, list[0] ? list[0] : "");
 	debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
 	return (char*)list;
 }
diff --git a/shell/hush_test/hush-misc/eval2.right b/shell/hush_test/hush-misc/eval2.right
new file mode 100644
index 0000000..a7ce6cc
--- /dev/null
+++ b/shell/hush_test/hush-misc/eval2.right
@@ -0,0 +1,3 @@
+Zero:0
+Zero:0
+Zero:0
diff --git a/shell/hush_test/hush-misc/eval2.tests b/shell/hush_test/hush-misc/eval2.tests
new file mode 100755
index 0000000..6bfb87a
--- /dev/null
+++ b/shell/hush_test/hush-misc/eval2.tests
@@ -0,0 +1,4 @@
+false; eval; echo Zero:$?
+false; eval ""; echo Zero:$?
+false; eval "
+"; echo Zero:$?