Merge pull request #1486 from iij/pr-typeerror-string-start-end-with

Crash if you call String#start_with/end_with with non-String arguments.

include/mruby/string.h

@@ -41,6 +41,7 @@ mrb_value mrb_ptr_to_str(mrb_state *, void *);
 mrb_value mrb_obj_as_string(mrb_state *mrb, mrb_value obj);
 mrb_value mrb_str_resize(mrb_state *mrb, mrb_value str, mrb_int len);
 mrb_value mrb_str_substr(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len);
+mrb_value mrb_string_type(mrb_state *mrb, mrb_value str);
 mrb_value mrb_check_string_type(mrb_state *mrb, mrb_value str);
 mrb_value mrb_str_buf_new(mrb_state *mrb, mrb_int capa);
 mrb_value mrb_str_buf_cat(mrb_state *mrb, mrb_value str, const char *ptr, size_t len);

mrbgems/mruby-string-ext/src/string.c

@@ -112,16 +112,19 @@ mrb_str_concat2(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_str_start_with(mrb_state *mrb, mrb_value self)
 {
-  mrb_value *argv;
+  mrb_value *argv, sub;
   int argc, i;
   mrb_get_args(mrb, "*", &argv, &argc);
 
   for (i = 0; i < argc; i++) {
     size_t len_l, len_r;
+    int ai = mrb_gc_arena_save(mrb);
+    sub = mrb_string_type(mrb, argv[i]);
+    mrb_gc_arena_restore(mrb, ai);
     len_l = RSTRING_LEN(self);
-    len_r = RSTRING_LEN(argv[i]);
+    len_r = RSTRING_LEN(sub);
     if (len_l >= len_r) {
-      if (memcmp(RSTRING_PTR(self), RSTRING_PTR(argv[i]), len_r) == 0) {
+      if (memcmp(RSTRING_PTR(self), RSTRING_PTR(sub), len_r) == 0) {
         return mrb_true_value();
       }
     }
@@ -138,17 +141,20 @@ mrb_str_start_with(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_str_end_with(mrb_state *mrb, mrb_value self)
 {
-  mrb_value *argv;
+  mrb_value *argv, sub;
   int argc, i;
   mrb_get_args(mrb, "*", &argv, &argc);
 
   for (i = 0; i < argc; i++) {
     size_t len_l, len_r;
+    int ai = mrb_gc_arena_save(mrb);
+    sub = mrb_string_type(mrb, argv[i]);
+    mrb_gc_arena_restore(mrb, ai);
     len_l = RSTRING_LEN(self);
-    len_r = RSTRING_LEN(argv[i]);
+    len_r = RSTRING_LEN(sub);
     if (len_l >= len_r) {
       if (memcmp(RSTRING_PTR(self) + (len_l - len_r),
-                 RSTRING_PTR(argv[i]),
+                 RSTRING_PTR(sub),
                  len_r) == 0) {
         return mrb_true_value();
       }  

mrbgems/mruby-string-ext/test/string.rb

@@ -105,10 +105,12 @@ assert('String#start_with?') do
   assert_true "hello".start_with?("heaven", "hell")
   assert_true !"hello".start_with?("heaven", "paradise")
   assert_true !"h".start_with?("heaven", "hell")
+  assert_raise TypeError do "hello".start_with?(true) end
 end
 
 assert('String#end_with?') do
   assert_true "string".end_with?("ing", "mng")
   assert_true !"string".end_with?("str", "tri")
   assert_true !"ng".end_with?("ing", "mng")
+  assert_raise TypeError do "hello".end_with?(true) end
 end

src/string.c

@@ -1524,6 +1524,12 @@ mrb_ptr_to_str(mrb_state *mrb, void *p)
   return mrb_obj_value(p_str);
 }
 
+mrb_value
+mrb_string_type(mrb_state *mrb, mrb_value str)
+{
+  return mrb_convert_type(mrb, str, MRB_TT_STRING, "String", "to_str");
+}
+
 mrb_value
 mrb_check_string_type(mrb_state *mrb, mrb_value str)
 {