From: Alex Rousskov <rousskov@measurement-factory.com>
Date: Sat, 29 Jul 2023 17:44:59 +0000 (+0000)
Subject: Bug 5290: pure virtual call in Ftp::Client constructor (#1429)
X-Git-Tag: SQUID_6_2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1da3adbdd88d3c6663092c4dbd01c0ef542b1d9;p=thirdparty%2Fsquid.git

Bug 5290: pure virtual call in Ftp::Client constructor (#1429)

    FATAL: Dying from an exception handling failure;
    exception: [no active exception]

Converting `this` to CbcPointer in a constructor of an abstract class
like Ftp::Client does not work because our virtual toCbdata() method
remains pure until the final/child class constructor runs.

Conceptually, the bug was probably introduced in 2013 commit 434a79b,
when FTP class hierarchy grew, making Ftp::Client an abstract class, but
the trigger was recent commit 337b9aa that removed CBDATA_CLASS() from
Ftp::Client class declaration. We discovered, described, and addressed
several such bugs in that commit, but we missed this case.
---

diff --git a/src/clients/FtpClient.h b/src/clients/FtpClient.h
index cbe0e58538..0db3b2da04 100644
--- a/src/clients/FtpClient.h
+++ b/src/clients/FtpClient.h
@@ -109,6 +109,8 @@ public:
 /// FTP client functionality shared among FTP Gateway and Relay clients.
 class Client: public ::Client
 {
+    CBDATA_INTERMEDIATE();
+
 public:
     explicit Client(FwdState *fwdState);
     ~Client() override;