Bug 238149
| Summary: | Variable in top level block scope is incorrectly captured | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | neildhar |
| Component: | JavaScriptCore | Assignee: | Nobody <webkit-unassigned> |
| Status: | RESOLVED WORKSFORME | ||
| Severity: | Normal | CC: | jarred, saam, webkit-bug-importer, ysuzuki |
| Priority: | P2 | Keywords: | InRadar |
| Version: | Safari 15 | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
neildhar
For the following snippet placed at the top level:
do {
let w = "banana";
function foo(){
w = "bar";
}
foo();
console.log(w);
} while(0)
JSC prints "banana", instead of "bar".
| Attachments | ||
|---|---|---|
| Add attachment proposed patch, testcase, etc. |
Radar WebKit Bug Importer
<rdar://problem/90639204>
Jarred Sumner
This seems to only happen when strict mode is off.
The following code doesn't reproduce the issue in jsc shell:
"use strict";
do {
let w = "banana";
function foo() {
w = "bar";
}
foo();
print(w);
} while (0);
But this code does:
do {
let w = "banana";
function foo() {
w = "bar";
}
foo();
print(w);
} while (0);
uncomment
The variable is not even visible within the function:
do {
let w = "banana";
function foo(){
console.log(w);
}
foo();
} while(0)
Result (unexpected): ReferenceError: Can't find variable: w
Unlike with arrow function:
do {
let w = "banana";
foo=()=>{
console.log(w);
};
foo();
} while(0)
Result (as expected): banana
Yusuke Suzuki
Now function declaration with the scope is implemented (instead of function statement). So it is fixed.