From 910fecf695e76c7b45a69cb3630ca2d2a3b86121 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Date: Mon, 11 Nov 2024 21:07:33 +0100
Subject: [PATCH] Add missing feature tests to the test suite

Check for chmod, hardlink, symlink, and special character support to
prevent test suite failures in feature constrained environments.

Thanks to Bruno Haible and Nelson H. F. Beebe for their testing and
analysis.

* tests/test-lib.sh: Add new feature tests.
* tests/hardlinks: Split this hardlinks related test off from
tests/remember-backup-files.
* tests/Makefile.am (TESTS): Add new hardlinks test here.
* tests/file-create-modes, tests/file-modes, tests/read-only-files,
tests/preserve-mode-and-timestamp, tests/no-mode-change-git-diff: These
tests require chmod support.
* tests/hardlinks, tests/unmodified-files: These tests require hardlink
support.
* tests/symlinks: This test requires symlink support.
* tests/quoted-filenames: This test requires special character support
in filenames.
---
 tests/Makefile.am                 |  1 +
 tests/file-create-modes           |  1 +
 tests/file-modes                  |  1 +
 tests/hardlinks                   | 50 ++++++++++++++++++++++++++++++
 tests/no-mode-change-git-diff     |  1 +
 tests/preserve-mode-and-timestamp |  1 +
 tests/quoted-filenames            |  4 ++-
 tests/read-only-files             |  1 +
 tests/remember-backup-files       | 35 ---------------------
 tests/symlinks                    |  1 +
 tests/test-lib.sh                 | 51 +++++++++++++++++++++++++++++--
 tests/unmodified-files            |  1 +
 12 files changed, 109 insertions(+), 39 deletions(-)
 create mode 100644 tests/hardlinks

diff --git a/tests/Makefile.am b/tests/Makefile.am
index fdc1639..bd3e330 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -42,6 +42,7 @@ TESTS = \
 	git-cleanup \
 	garbage \
 	global-reject-files \
+	hardlinks \
 	inname \
 	line-numbers \
 	merge \
diff --git a/tests/file-create-modes b/tests/file-create-modes
index 2ea44ec..e80a79a 100644
--- a/tests/file-create-modes
+++ b/tests/file-create-modes
@@ -10,6 +10,7 @@
 
 require cat
 require sed
+require chmod
 use_local_patch
 use_tmpdir
 
diff --git a/tests/file-modes b/tests/file-modes
index 8475182..9c28dd8 100644
--- a/tests/file-modes
+++ b/tests/file-modes
@@ -10,6 +10,7 @@
 
 require cat
 require sed
+require chmod
 use_local_patch
 use_tmpdir
 
diff --git a/tests/hardlinks b/tests/hardlinks
new file mode 100644
index 0000000..7eb3a28
--- /dev/null
+++ b/tests/hardlinks
@@ -0,0 +1,50 @@
+# Copyright 2009-2024 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# in any medium, are permitted without royalty provided the copyright
+# notice and this notice are preserved.
+
+# Patch must not overwrite backup files it has created itself.
+# (Backup file tests for symlinks are in tests/symlinks.)
+
+. $srcdir/test-lib.sh
+
+require cat
+require hardlinks
+use_local_patch
+use_tmpdir
+
+# ==============================================================
+
+# Hardlinks between source files
+
+echo one > f
+ln f g
+
+cat > fg.diff <<EOF
+--- f.orig
++++ f
+@@ -2 +2 @@
+-one
++two
+--- g.orig
++++ g
+@@ -2 +2 @@
+-one
++two
+EOF
+
+check 'patch -p0 < fg.diff' <<EOF
+patching file f
+Hunk #1 succeeded at 1 (offset -1 lines).
+patching file g
+Hunk #1 succeeded at 1 (offset -1 lines).
+EOF
+
+check 'cat f.orig' <<EOF
+one
+EOF
+
+check 'cat g.orig' <<EOF
+one
+EOF
diff --git a/tests/no-mode-change-git-diff b/tests/no-mode-change-git-diff
index 50497e0..eaf860b 100644
--- a/tests/no-mode-change-git-diff
+++ b/tests/no-mode-change-git-diff
@@ -9,6 +9,7 @@
 require cat
 require chmod
 require stat
+require chmod
 use_local_patch
 use_tmpdir
 
diff --git a/tests/preserve-mode-and-timestamp b/tests/preserve-mode-and-timestamp
index 07d4370..7e8ff84 100644
--- a/tests/preserve-mode-and-timestamp
+++ b/tests/preserve-mode-and-timestamp
@@ -8,6 +8,7 @@
 
 require cat
 require sed
+require chmod
 use_local_patch
 use_tmpdir
 
diff --git a/tests/quoted-filenames b/tests/quoted-filenames
index ec1d376..54982da 100644
--- a/tests/quoted-filenames
+++ b/tests/quoted-filenames
@@ -9,13 +9,15 @@
 . $srcdir/test-lib.sh
 
 require cat
+require special_characters
 use_local_patch
 use_tmpdir
 
 # ==============================================================
 
 # Forbidden characters in Windows filenames:
-#   \ / : * ? " < > |
+#   \ / : * ? " < > | TAB
+# Filenames with trailing space characters
 
 cat > d.diff <<EOF
 --- "\\t \\040"
diff --git a/tests/read-only-files b/tests/read-only-files
index f188a3d..b28b93d 100644
--- a/tests/read-only-files
+++ b/tests/read-only-files
@@ -9,6 +9,7 @@
 . $srcdir/test-lib.sh
 
 require cat
+require chmod
 use_local_patch
 use_tmpdir
 
diff --git a/tests/remember-backup-files b/tests/remember-backup-files
index 13406fa..e8d7f25 100644
--- a/tests/remember-backup-files
+++ b/tests/remember-backup-files
@@ -50,41 +50,6 @@ EOF
 
 # ==============================================================
 
-# Hardlinks between source files
-
-echo one > f
-ln f g
-
-cat > fg.diff <<EOF
---- f.orig
-+++ f
-@@ -2 +2 @@
--one
-+two
---- g.orig
-+++ g
-@@ -2 +2 @@
--one
-+two
-EOF
-
-check 'patch -p0 < fg.diff' <<EOF
-patching file f
-Hunk #1 succeeded at 1 (offset -1 lines).
-patching file g
-Hunk #1 succeeded at 1 (offset -1 lines).
-EOF
-
-check 'cat f.orig' <<EOF
-one
-EOF
-
-check 'cat g.orig' <<EOF
-one
-EOF
-
-# ==============================================================
-
 echo one > f
 
 cat > f.diff <<EOF
diff --git a/tests/symlinks b/tests/symlinks
index aff283a..daca8a3 100644
--- a/tests/symlinks
+++ b/tests/symlinks
@@ -9,6 +9,7 @@
 . $srcdir/test-lib.sh
 
 require cat
+require symlinks
 use_local_patch
 use_tmpdir
 
diff --git a/tests/test-lib.sh b/tests/test-lib.sh
index 7fb1363..ba755dc 100644
--- a/tests/test-lib.sh
+++ b/tests/test-lib.sh
@@ -7,7 +7,7 @@
 
 # FIXME: Requires a version of diff that understands "-u".
 
-require_gnu_diff() {
+_require_gnu_diff() {
     case "`diff --version 2> /dev/null`" in
     *GNU*)
 	;;
@@ -17,10 +17,55 @@ require_gnu_diff() {
     esac
 }
 
+_try_chmod() {
+    chmod "$1" "$2" && test "`ls -l "$2" | cut -b2-10`" = "$3"
+}
+
+_require_chmod() {
+    tmp=`mktemp working-chmod.XXXXXXXX`
+    if ! _try_chmod 644 "$tmp" "rw-r--r--" || \
+       ! _try_chmod 600 "$tmp" "rw-------"; then
+	rm -f "$tmp"
+	echo "This test requires chmod support" >&2
+	exit 77
+    fi
+    rm -f "$tmp"
+}
+
+_require_hardlinks() {
+    tmpdir=`mktemp -d hardlinks.XXXXXXXX`
+    if ! touch "$tmpdir/f" ||
+       ! ln "$tmpdir/f" "$tmpdir/g"; then
+	rm -rf "$tmpdir"
+	echo "This test requires hardlink support" >&2
+	exit 77
+    fi
+    rm -rf "$tmpdir"
+}
+
+_require_symlinks() {
+    tmpdir=`mktemp -d hardlinks.XXXXXXXX`
+    if ! touch "$tmpdir/f" ||
+       ! ln -s "f" "$tmpdir/g"; then
+	rm -rf "$tmpdir"
+	echo "This test requires symlink support" >&2
+	exit 77
+    fi
+    rm -rf "$tmpdir"
+}
+
+_require_special_characters() {
+    if ! tmp=`mktemp '	 '.XXXXXXXX`; then
+	echo "This test requires special character support in filenames" >&2
+	exit 77
+    fi
+    rm -f "$tmp"
+}
+
 require() {
     utility="$1"
-    if type require_${utility} > /dev/null 2> /dev/null; then
-	require_${utility}
+    if type _require_${utility} > /dev/null 2> /dev/null; then
+	_require_${utility}
     elif ! type "${utility}" > /dev/null 2> /dev/null; then
 	echo "This test requires the ${utility} utility" >&2
 	exit 77
diff --git a/tests/unmodified-files b/tests/unmodified-files
index 93d078a..77cb8bc 100644
--- a/tests/unmodified-files
+++ b/tests/unmodified-files
@@ -7,6 +7,7 @@
 . $srcdir/test-lib.sh
 
 require cat
+require hardlinks
 use_local_patch
 use_tmpdir