util: fix inspected stack indentation

Error stacks and multiline error messages were not correct indented.
This is fixed by this patch.

lib/util.js

@@ -590,6 +590,11 @@ function formatValue(ctx, value, recurseTimes) {
       if (base.indexOf('\n    at') === -1) {
         base = `[${base}]`;
       }
+      // The message and the stack have to be indented as well!
+      if (ctx.indentationLvl !== 0) {
+        const indentation = ' '.repeat(ctx.indentationLvl);
+        base = formatError(value).replace(/\n/g, `\n${indentation}`);
+      }
       if (keyLength === 0)
         return base;
     } else if (isAnyArrayBuffer(value)) {

test/message/util_inspect_error.js

@@ -0,0 +1,12 @@
+'use strict';
+
+require('../common');
+const util = require('util');
+
+const err = new Error('foo\nbar');
+
+console.log(util.inspect({ err, nested: { err } }, { compact: true }));
+console.log(util.inspect({ err, nested: { err } }, { compact: false }));
+
+err.foo = 'bar';
+console.log(util.inspect(err, { compact: true, breakLength: 5 }));

test/message/util_inspect_error.out

@@ -0,0 +1,63 @@
+{ err:
+   Error: foo
+   bar
+       at *util_inspect_error*
+       at *
+       at *
+       at *
+       at *
+       at *
+       at *
+       at *
+       at *
+  nested:
+   { err:
+      Error: foo
+      bar
+          at *util_inspect_error*
+          at *
+          at *
+          at *
+          at *
+          at *
+          at *
+          at *
+          at * } }
+{
+  err: Error: foo
+  bar
+      at *util_inspect_error*
+      at *
+      at *
+      at *
+      at *
+      at *
+      at *
+      at *
+      at *,
+  nested: {
+    err: Error: foo
+    bar
+        at *util_inspect_error*
+        at *
+        at *
+        at *
+        at *
+        at *
+        at *
+        at *
+        at *
+  }
+}
+{ Error: foo
+bar
+    at *util_inspect_error*
+    at *
+    at *
+    at *
+    at *
+    at *
+    at *
+    at *
+    at *
+  foo: 'bar' }