From 4ff36552f6e9cc0c62e7dacc2ca6ff3e87ad10b5 Mon Sep 17 00:00:00 2001
From: Adrian Ho <the.gromgit@gmail.com>
Date: Fri, 5 Jul 2024 10:59:36 +0800
Subject: [PATCH] shellenv: prepend colon to MANPATH if set

The current appended colon means system man pages always shadow
Homebrew's. There's also no point adding Homebrew's man dir, nor
filling out an empty MANPATH, since `man` and friends will add the
necessary dirs according to PATH.

Closes https://github.com/Homebrew/homebrew-core/issues/176037.

Also fixed a syntax error in the `*csh` INFOPATH setting.
---
 Library/Homebrew/cmd/shellenv.sh | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Library/Homebrew/cmd/shellenv.sh b/Library/Homebrew/cmd/shellenv.sh
index 6e600df09d3ac..63e53774c5441 100644
--- a/Library/Homebrew/cmd/shellenv.sh
+++ b/Library/Homebrew/cmd/shellenv.sh
@@ -11,7 +11,7 @@
 
 # HOMEBREW_CELLAR and HOMEBREW_PREFIX are set by extend/ENV/super.rb
 # HOMEBREW_REPOSITORY is set by bin/brew
-# Trailing colon in MANPATH adds default man dirs to search path in Linux, does no harm in macOS.
+# Leading colon in MANPATH prepends default man dirs to search path in Linux and macOS.
 # Please do not submit PRs to remove it!
 # shellcheck disable=SC2154
 homebrew-shellenv() {
@@ -33,7 +33,7 @@ homebrew-shellenv() {
       echo "set -gx HOMEBREW_CELLAR \"${HOMEBREW_CELLAR}\";"
       echo "set -gx HOMEBREW_REPOSITORY \"${HOMEBREW_REPOSITORY}\";"
       echo "fish_add_path -gP \"${HOMEBREW_PREFIX}/bin\" \"${HOMEBREW_PREFIX}/sbin\";"
-      echo "! set -q MANPATH; and set MANPATH ''; set -gx MANPATH \"${HOMEBREW_PREFIX}/share/man\" \$MANPATH;"
+      echo "set -q MANPATH; and set MANPATH[1] \":\$(string trim --left --chars=\":\" \$MANPATH[1])\";"
       echo "! set -q INFOPATH; and set INFOPATH ''; set -gx INFOPATH \"${HOMEBREW_PREFIX}/share/info\" \$INFOPATH;"
       ;;
     csh | -csh | tcsh | -tcsh)
@@ -41,8 +41,8 @@ homebrew-shellenv() {
       echo "setenv HOMEBREW_CELLAR ${HOMEBREW_CELLAR};"
       echo "setenv HOMEBREW_REPOSITORY ${HOMEBREW_REPOSITORY};"
       echo "setenv PATH ${HOMEBREW_PREFIX}/bin:${HOMEBREW_PREFIX}/sbin:\$PATH;"
-      echo "setenv MANPATH ${HOMEBREW_PREFIX}/share/man\`[ \${?MANPATH} == 1 ] && echo \":\${MANPATH}\"\`:;"
-      echo "setenv INFOPATH ${HOMEBREW_PREFIX}/share/info\`[ \${?INFOPATH} == 1 ] && echo \":\${INFOPATH}\"\`;"
+      echo "if ( \${?MANPATH} == 1 ) setenv MANPATH :\${MANPATH};"
+      echo "setenv INFOPATH ${HOMEBREW_PREFIX}/share/info\`if ( \${?INFOPATH} == 1 ) echo \":\${INFOPATH}\"\`;"
       ;;
     pwsh | -pwsh | pwsh-preview | -pwsh-preview)
       echo "[System.Environment]::SetEnvironmentVariable('HOMEBREW_PREFIX','${HOMEBREW_PREFIX}',[System.EnvironmentVariableTarget]::Process)"
@@ -57,7 +57,7 @@ homebrew-shellenv() {
       echo "export HOMEBREW_CELLAR=\"${HOMEBREW_CELLAR}\";"
       echo "export HOMEBREW_REPOSITORY=\"${HOMEBREW_REPOSITORY}\";"
       echo "export PATH=\"${HOMEBREW_PREFIX}/bin:${HOMEBREW_PREFIX}/sbin\${PATH+:\$PATH}\";"
-      echo "export MANPATH=\"${HOMEBREW_PREFIX}/share/man\${MANPATH+:\$MANPATH}:\";"
+      echo "[ -z \"\${MANPATH}\" ] || export MANPATH=\":\${MANPATH#:}\";"
       echo "export INFOPATH=\"${HOMEBREW_PREFIX}/share/info:\${INFOPATH:-}\";"
       ;;
   esac