CEF force-creates a Downloads directory in user directory

[magreenblatt]

Original report by Henri Beauchamp (Bitbucket: Henri Beauchamp).

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Greetings,

In recent CEF versions (v81+, at least), CEF force-creates a “Downloads” directory when launched, even though:

• Such a directory is not needed at all for applications not allowing to download anything via CEF (e.g. the Second Life viewer), and yet CEF creates it even before any download is requested.
• The algorithm to determine whether a downloads directory is “safe” or not is totally flawed (why the Hell would the home user directory be considered “dangerous” at all ?).
• It is NOT the business of an application to decide what the directory tree of a user should be.

The culprit code is (currently, i.e. for CEF v88) in chromium_git/cef/libcef/common/resource_util.cc, namely the DownloadPathIsDangerous() function.

I suggest that at least one of the following fixes is applied to future CEF versions (in preference order):

• Remove that function altogether and let the it be user's responsibility to choose how they manage their own files.
• Make the DownloadPathIsDangerous() check only active following the activation of a runtime option.
• Instead of creating a Downloads directory, and when the current directory is considered “dangerous”, point the default download path to a “safe” directory (e.g. the one pointed by $TEMP) as a suggested destination.
• Offer an option to disable entirely the DownloadPathIsDangerous() check at runtime.
• Keep creating the “Downloads” directory, but only when a download is actually attempted !

Thank you.

‌

[magreenblatt]

Original changes by Henri Beauchamp (Bitbucket: Henri Beauchamp).

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• edited description

[magreenblatt]

Original changes by Henri Beauchamp (Bitbucket: Henri Beauchamp).

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• edited description

[magreenblatt]

Original changes by Henri Beauchamp (Bitbucket: Henri Beauchamp).

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• edited description

[magreenblatt]

Original changes by Henri Beauchamp (Bitbucket: Henri Beauchamp).

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• edited description

[magreenblatt]

It’s the call to base::PathService::Override in OverrideDefaultDownloadDir that creates the directory. The viable alternatives include:

1. Using a different path (like TEMP) if the safe directory does not already exist.
2. Using OverrideAndCreateIfNeeded instead of Override to create the directory later, if needed. This will require testing to verify that it works as expected with the code in chrome/browser/download/download_prefs.cc.

A PR is welcome if you would like to implement this.

[magreenblatt]

• changed title from "CEF force-creates a Donwloads directory in user directory" to "CEF force-creates a Downloads directory in user directory"

[magreenblatt]

Alloy bootstrap is removed in M128 (see #3685)