[pacman-dev] [PATCH] makepkg: correctly handle missing download clients

[Eli Schwartz]

This was broken in commit 882e707e40bbade0111cf3bdedbdac4d4b70453b,
which changed 'plain()' messages to go to stdout, which was then
captured as the download client in question: cmdline=("Aborting...").

The result was a very confusing error message e.g.

/usr/share/makepkg/source/file.sh: line 72: $'\E[1m': command not found

or with makepkg --nocolor:

/usr/share/makepkg/source/file.sh: line 72: Aborting...: command not found

Solve this on two levels:
- redirect this error() continuation to stderr so the user sees it.
- catch erroring returns in get_downloadclient and propagate them

bash 4.4 can use wait $! to retrieve the return value of an asynchronous
subshell such as <(...), which means, now we target that as our minimum,
we can sanely handle errors in such functions.

Signed-off-by: Eli Schwartz <eschwartz at archlinux.org>
---

Actually, maybe every use of plain() needs to do this. Or else make
plain() do this by default. But it's technically used to "continue the
previous message", and there's no guarantee it merits going to stderr,
even though every time we use plain(), it does.

What to do...

 scripts/libmakepkg/source/file.sh.in | 1 +
 scripts/libmakepkg/util/source.sh.in | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/libmakepkg/source/file.sh.in b/scripts/libmakepkg/source/file.sh.in
index 819320c2..28f373fb 100644
--- a/scripts/libmakepkg/source/file.sh.in
+++ b/scripts/libmakepkg/source/file.sh.in
@@ -42,6 +42,7 @@ download_file() {
 	# find the client we should use for this URL
 	local -a cmdline
 	IFS=' ' read -a cmdline < <(get_downloadclient "$proto")
+	wait $! || exit
 	(( ${#cmdline[@]} )) || exit
 
 	local filename=$(get_filename "$netfile")
diff --git a/scripts/libmakepkg/util/source.sh.in b/scripts/libmakepkg/util/source.sh.in
index e0490661..1bf5b814 100644
--- a/scripts/libmakepkg/util/source.sh.in
+++ b/scripts/libmakepkg/util/source.sh.in
@@ -165,7 +165,7 @@ get_downloadclient() {
 	if [[ ! -x $program ]]; then
 		local baseprog="${program##*/}"
 		error "$(gettext "The download program %s is not installed.")" "$baseprog"
-		plain "$(gettext "Aborting...")"
+		plain "$(gettext "Aborting...")" >&2
 		exit 1 # $E_MISSING_PROGRAM
 	fi
 
-- 
2.26.2