docs: update when `git bisect visualize` uses `gitk`

This check has involved more environment variables than just `DISPLAY` since
508e84a790 (bisect view: check for MinGW32 and MacOSX in addition to X11,
2008-02-14), so let's update the documentation accordingly.

Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
index fbb39fbdf5d62a455c8b62d4870817998d0434ad..7872dba3aefa3de62175f0e88bfac1473bbe0723 100644 (file)
--- a/Documentation/git-bisect.txt
+++ b/Documentation/git-bisect.txt
@@ -204,9 +204,14 @@ as an alternative to `visualize`):
 $ git bisect visualize
 ------------
 
-If the `DISPLAY` environment variable is not set, 'git log' is used
-instead.  You can also give command-line options such as `-p` and
-`--stat`.
+Git detects a graphical environment through various environment variables:
+`DISPLAY`, which is set in X Window System environments on Unix systems.
+`SESSIONNAME`, which is set under Cygwin in interactive desktop sessions.
+`MSYSTEM`, which is set under Msys2 and Git for Windows.
+`SECURITYSESSIONID`, which may be set on macOS in interactive desktop sessions.
+
+If none of these environment variables is set, 'git log' is used instead.
+You can also give command-line options such as `-p` and `--stat`.
 
 ------------
 $ git bisect visualize --stat