Move the `_which` function (almost) to the top
We are about to make use of the `_which` function to address
CVE-2022-41953 by overriding Tcl/Tk's unsafe PATH lookup on Windows.
In preparation for that, let's move it close to the top of the file to
make sure that even early `exec` calls that happen during the start-up
of Git GUI benefit from the fix.
This commit is best viewed with `--color-moved`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
diff --git a/git-gui.sh b/git-gui.sh
index f779fc9..b0eb5a6 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -77,6 +77,52 @@
######################################################################
##
+## PATH lookup
+
+set _search_path {}
+proc _which {what args} {
+ global env _search_exe _search_path
+
+ if {$_search_path eq {}} {
+ if {[is_Cygwin] && [regexp {^(/|\.:)} $env(PATH)]} {
+ set _search_path [split [exec cygpath \
+ --windows \
+ --path \
+ --absolute \
+ $env(PATH)] {;}]
+ set _search_exe .exe
+ } elseif {[is_Windows]} {
+ set gitguidir [file dirname [info script]]
+ regsub -all ";" $gitguidir "\\;" gitguidir
+ set env(PATH) "$gitguidir;$env(PATH)"
+ set _search_path [split $env(PATH) {;}]
+ # Skip empty `PATH` elements
+ set _search_path [lsearch -all -inline -not -exact \
+ $_search_path ""]
+ set _search_exe .exe
+ } else {
+ set _search_path [split $env(PATH) :]
+ set _search_exe {}
+ }
+ }
+
+ if {[is_Windows] && [lsearch -exact $args -script] >= 0} {
+ set suffix {}
+ } else {
+ set suffix $_search_exe
+ }
+
+ foreach p $_search_path {
+ set p [file join $p $what$suffix]
+ if {[file exists $p]} {
+ return [file normalize $p]
+ }
+ }
+ return {}
+}
+
+######################################################################
+##
## locate our library
if { [info exists ::env(GIT_GUI_LIB_DIR) ] } {
@@ -194,7 +240,6 @@
set _gitexec {}
set _githtmldir {}
set _reponame {}
-set _search_path {}
set _shellpath {@@SHELL_PATH@@}
set _trace [lsearch -exact $argv --trace]
@@ -444,47 +489,6 @@
return $v
}
-proc _which {what args} {
- global env _search_exe _search_path
-
- if {$_search_path eq {}} {
- if {[is_Cygwin] && [regexp {^(/|\.:)} $env(PATH)]} {
- set _search_path [split [exec cygpath \
- --windows \
- --path \
- --absolute \
- $env(PATH)] {;}]
- set _search_exe .exe
- } elseif {[is_Windows]} {
- set gitguidir [file dirname [info script]]
- regsub -all ";" $gitguidir "\\;" gitguidir
- set env(PATH) "$gitguidir;$env(PATH)"
- set _search_path [split $env(PATH) {;}]
- # Skip empty `PATH` elements
- set _search_path [lsearch -all -inline -not -exact \
- $_search_path ""]
- set _search_exe .exe
- } else {
- set _search_path [split $env(PATH) :]
- set _search_exe {}
- }
- }
-
- if {[is_Windows] && [lsearch -exact $args -script] >= 0} {
- set suffix {}
- } else {
- set suffix $_search_exe
- }
-
- foreach p $_search_path {
- set p [file join $p $what$suffix]
- if {[file exists $p]} {
- return [file normalize $p]
- }
- }
- return {}
-}
-
# Test a file for a hashbang to identify executable scripts on Windows.
proc is_shellscript {filename} {
if {![file exists $filename]} {return 0}
