From 32134f1512eab90da01e9cfd9f676bffef27a939 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@tuebingen.mpg.de>
Date: Wed, 20 Jan 2016 10:54:35 +0100
Subject: [PATCH] Add gsu_make_tempfile() and fix bug in gui module.

While mkstemp(3) is required by POSIX.1-2001, mktemp(1) is not in POSIX
and the various Unixes ship different and incompatible implementations
of this command line utility.

This commit adds the new public gsu_make_tempfile() helper to the
common part of gsu and changes the gui module to use it.

The mktemp invocation in the gui module was buggy because it ran
mktemp with a relative template (no slash). Hence the temporary file
was created in the current working directory. Of course this fails
if $CWD is not writable. The new public function gets this right.
---
 common | 32 ++++++++++++++++++++++++++++++++
 gui    | 12 +++++-------
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/common b/common
index d418095..4e1d115 100644
--- a/common
+++ b/common
@@ -90,3 +90,35 @@ _gsu_setup()
 	gsu_banner_txt="${gsu_banner_txt:-set \$gsu_banner_txt to customize this message}"
 	_gsu_init_errors
 }
+
+# We'd love to use mktemp -t here, but on Linux -t is deprecated in favor of
+# --tempdir, which is not supported on *BSD. Hence we have to implement our own
+# logic for -t.
+#
+# The second parameter to this function is optional. It is ignored if the
+# template ($1) is an absolute path. Conversely, if the template is a relative
+# path and a second parameter is given, $2 is assumed to be the directory in
+# which the temporary file should be created.
+gsu_make_tempfile()
+{
+	local template="$1"
+	local dir
+
+	if [[ "${template:0:1}" != '/' ]]; then # relative path
+		if (($# > 1)); then
+			dir="$2"
+		elif [[ -n "$TMPDIR" ]]; then
+			dir="$TMPDIR"
+		else
+			dir="/tmp"
+		fi
+		template="$dir/$template"
+	fi
+	result="$(mktemp "$template")"
+	if (($? != 0)); then
+		ret=-$E_GSU_MKTEMP
+		result="template: $template"
+		return
+	fi
+	ret=$GSU_SUCCESS
+}
diff --git a/gui b/gui
index fa3ae48..34f732e 100644
--- a/gui
+++ b/gui
@@ -80,15 +80,13 @@ gsu_textbox()
 # This is like gsu_textbox() but the text is passed as a string.
 gsu_msgbox()
 {
+	local tmp
+
 	# Some versions of dialog segfault if the text is too long. Hence we
 	# always use a temporary file.
-	local tmp="$(mktemp gsu_msgbox.XXXXXXXXXX)"
-
-	if (($? != 0)); then
-		ret=-$E_GSU_MKTEMP
-		result='temp file for textbox'
-		return
-	fi
+	gsu_make_tempfile 'gsu_msgbox.XXXXXXXXXX'
+	(($ret < 0)) && return
+	tmp="$result"
 	trap "rm -f $tmp" EXIT
 	echo "$1" > "$tmp"
 	gsu_textbox "$tmp"
-- 
2.39.5