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fix corner case in merge_vars (#4131)

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fixes #4130
This commit is contained in:
Alex Lam S.L
2020-09-19 22:36:16 +01:00
committed by GitHub
parent 3c609e2f4a
commit 171c544705
2 changed files with 52 additions and 6 deletions
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19
lib/compress.js
View File

@@ -4358,6 +4358,7 @@ merge(Compressor.prototype, {
if (node.init) node.init.walk(tw);
push();
segment.block = node;
segment.loop = true;
if (node.condition) node.condition.walk(tw);
node.body.walk(tw);
if (node.step) node.step.walk(tw);
@@ -4368,6 +4369,7 @@ merge(Compressor.prototype, {
node.object.walk(tw);
push();
segment.block = node;
segment.loop = true;
node.init.walk(tw);
node.body.walk(tw);
pop();
@@ -4388,6 +4390,7 @@ merge(Compressor.prototype, {
if (node instanceof AST_IterationStatement) {
push();
segment.block = node;
segment.loop = true;
descend();
pop();
return true;
@@ -4400,12 +4403,15 @@ merge(Compressor.prototype, {
return true;
}
if (node instanceof AST_Scope) {
if (node instanceof AST_Lambda) {
references[node.variables.get("arguments").id] = false;
if (node.name) references[node.name.definition().id] = false;
}
push();
segment.block = node;
if (node instanceof AST_Lambda) {
if (node.name) {
if (node !== self) segment.loop = true;
references[node.name.definition().id] = false;
}
references[node.variables.get("arguments").id] = false;
}
descend();
pop();
return true;
@@ -4487,7 +4493,9 @@ merge(Compressor.prototype, {
var id = tail.definition.id;
var tail_refs = references[id];
if (!tail_refs) continue;
if (!mergeable(head_refs, tail_refs)) {
if (head_refs.start.block !== tail_refs.start.block
|| !mergeable(head_refs, tail_refs)
|| head_refs.start.loop && !mergeable(tail_refs, head_refs)) {
skipped.unshift(tail);
continue;
}
@@ -4560,7 +4568,6 @@ merge(Compressor.prototype, {
}
function mergeable(head, tail) {
if (head.start.block !== tail.start.block) return false;
return must_visit(head.start, head.end) || must_visit(head.start, tail.start);
}
});

39
test/compress/merge_vars.js
View File

@@ -2662,3 +2662,42 @@ issue_4126_2: {
}
expect_stdout: "undefined"
}
issue_4130: {
options = {
merge_vars: true,
side_effects: true,
toplevel: true,
}
input: {
var a = 2;
while (a)
try {
console.log(a);
} catch (e) {
var b = 0;
} finally {
b && console.log("FAIL");
var c = --a;
for (var k in c)
c;
}
}
expect: {
var a = 2;
while (a)
try {
console.log(a);
} catch (e) {
var b = 0;
} finally {
b && console.log("FAIL");
var c = --a;
for (var k in c);
}
}
expect_stdout: [
"2",
"1",
]
}