Fix count variable calculation in typedarray copyWithin

szilagyiadam · szilagyiadam · commit ae11b80465fb · 2019-10-03T10:14:51.000+02:00
Fixes #3130 JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu
diff --git a/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c b/jerry-core/ecma/builtin-objects/typedarray/ecma-builtin-typedarray-prototype.c
@@ -1872,16 +1872,16 @@ ecma_builtin_typedarray_prototype_copy_within (ecma_value_t this_arg, /**< this
     }
   }
 
-  int32_t distance = (int32_t) (end - start);
-  int32_t offset = (int32_t) (info.typedarray_length - target);
-  int32_t count = JERRY_MIN (distance, offset);
-
   if (target >= info.typedarray_length || start >= end || end == 0)
   {
     return ecma_copy_value (this_arg);
   }
   else
   {
+    uint32_t distance = end - start;
+    uint32_t offset = info.typedarray_length - target;
+    uint32_t count = JERRY_MIN (distance, offset);
+
     memmove (info.buffer_p + (target * info.element_size),
              info.buffer_p + (start * info.element_size),
              (size_t) (count * info.element_size));

Original file line number	Diff line number	Diff line change
`@@ -1872,16 +1872,16 @@ ecma_builtin_typedarray_prototype_copy_within (ecma_value_t this_arg, /**< this`
`1872`	`1872`	`}`
`1873`	`1873`	`}`
`1874`	`1874`
`1875`		`- int32_t distance = (int32_t) (end - start);`
`1876`		`- int32_t offset = (int32_t) (info.typedarray_length - target);`
`1877`		`- int32_t count = JERRY_MIN (distance, offset);`
`1878`		`-`
`1879`	`1875`	`if (target >= info.typedarray_length \|\| start >= end \|\| end == 0)`
`1880`	`1876`	`{`
`1881`	`1877`	`return ecma_copy_value (this_arg);`
`1882`	`1878`	`}`
`1883`	`1879`	`else`
`1884`	`1880`	`{`
	`1881`	`+ uint32_t distance = end - start;`
	`1882`	`+ uint32_t offset = info.typedarray_length - target;`
	`1883`	`+ uint32_t count = JERRY_MIN (distance, offset);`
	`1884`	`+`
`1885`	`1885`	`memmove (info.buffer_p + (target * info.element_size),`
`1886`	`1886`	`info.buffer_p + (start * info.element_size),`
`1887`	`1887`	`(size_t) (count * info.element_size));`