bug#61942: 28.2; uninterruptible hang in vc-diff buffer

[Tom Tromey]

>From *vc-outgoing*, I used '=' to see a diff.

The diff in question is pretty large.

Emacs showed this in the echo area:

Finding changes in ....

This was not interruptible -- I tried C-g, C-], and 'kill -USR1'

I don't know exactly what this is doing, but whatever it is should be
interruptible.

Tom




In GNU Emacs 28.2 (build 1, x86_64-redhat-linux-gnu, GTK+ Version 3.24.35, 
cairo version 1.17.6)
 of 2022-12-31 built on buildvm-x86-18.iad2.fedoraproject.org
Windowing system distributor 'The X.Org Foundation', version 11.0.12201007
System Description: Fedora Linux 36 (Workstation Edition)

Configured using:
 'configure --build=x86_64-redhat-linux-gnu
 --host=x86_64-redhat-linux-gnu --program-prefix=
 --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr
 --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc
 --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64
 --libexecdir=/usr/libexec --localstatedir=/var
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 host_alias=x86_64-redhat-linux-gnu CC=gcc 'CFLAGS=-DMAIL_USE_LOCKF -O2
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 LDFLAGS=-Wl,-z,relro
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Configured features:
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LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NATIVE_COMP NOTIFY
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Important settings:
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Major mode: Git-Log-View

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Load-path shadows:
None found.

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Memory information:
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