Bug 1677088 replaced file reading code, and changed it to this syntax in several places:

String.fromCharCode(...(await IOUtils.read(file.path))

When attempting to import a 2 MB file, the code fails:

RangeError: too many function arguments
    EnigmailCommon_importObjectFromFile chrome://openpgp/content/ui/commonWorkflows.js:144

Can you please change all places with this approach to use code that supports bigger files?

This seems to work:

-      keyBlock = String.fromCharCode(...(await IOUtils.read(file.path)));
+
+      let data = await IOUtils.read(file.path);
+
+      keyBlock = "";
+      for (let i = 0; i < data.length; i++) {
+        keyBlock += String.fromCharCode(data[i]);
+      }

I introduced a uint8ArrayToByteString util a few days ago, https://searchfox.org/comm-central/rev/a0e7f418beb151ae9c0d6f24f88d2aa61ffdf0cd/mailnews/base/src/MailStringUtils.jsm#26

I'll take care of it. What an annoying trap!

String.fromCharCode doesn't like getting passed too many arguments, like one gets for megabytes of data.

please uplift to beta

Pushed by mkmelin@iki.fi:
https://hg.mozilla.org/comm-central/rev/3116051508f0
fix importing of large openpgp key files. r=kaie

Comment on attachment 9271233 [details]
Bug 1763258 - fix importing of large openpgp key files. r=kaie

[Triage Comment]
Approved for beta per Kai's request in comment 5.

Thunderbird 100.0b2:
https://hg.mozilla.org/releases/comm-beta/rev/a6ccaf95df90