[PATCH] pager: do not unnecessarily set COLUMNS on Windows

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Jun 14, 2021, 20:19 UTC
Message-ID: <pull.982.git.1623701952823.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

Since https://github.com/gwsw/less/commit/bb0ee4e76c2, `less` prefers the `COLUMNS` variable over asking ncurses itself.

This is typically not a problem because we ask `TIOCGWINSZ` in Git, to determine the correct value for `COLUMNS`.

However, on Windows it _is_ a problem because Git for Windows' Bash (and `less.exe`) uses the MSYS2 runtime while `git.exe` does _not_, and therefore we never get the correct value in Git, but `less.exe` has no problem obtaining it.

Let's not override `COLUMNS` in that case.

This fixes https://github.com/git-for-windows/git/issues/3235

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    pager: do not unnecessarily set COLUMNS on Windows
    
    A recent upgrade of the "less" package in Git for Windows causes
    problems. Here is a work-around.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-982%2Fdscho%2Ffix-duplicated-lines-when-moving-in-pager-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-982/dscho/fix-duplicated-lines-when-moving-in-pager-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/982

 pager.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pager.c b/pager.c
index 3d37dd7adaa2..b84668eddca2 100644
--- a/pager.c
+++ b/pager.c
@@ -111,11 +111,13 @@ void setup_pager(void)
 	 * to get the terminal size. Let's grab it now, and then set $COLUMNS
 	 * to communicate it to any sub-processes.
 	 */
+#if !defined(WIN32) || defined(TIOCGWINSZ)
 	{
 		char buf[64];
 		xsnprintf(buf, sizeof(buf), "%d", term_columns());
 		setenv("COLUMNS", buf, 0);
 	}
+#endif
 
 	setenv("GIT_PAGER_IN_USE", "true", 1);
 

base-commit: ebf3c04b262aa27fbb97f8a0156c2347fecafafb

-- 
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