test.tar: fix tar tests on Android.

There's no /etc/group on Android.

Loop devices are in different places, but that test doesn't seem to
offer anything beyond the block/char special device tests later, so
remove that rather than fix it.

Fix the block/char special tests (the expectations were missing, but
they're never normally run on the host because the mknod fails).

Likewise add the missing expectation to the "ownership" test, which
isn't normally run on the host because the chown fails.

The "sparse without overflow" test was broken because of the mksh/bash
disagreement about whether in `VAR=val shell_function` that's a
temporary assignment to VAR or one that outlives the command. Switch SUM
to being a function like LST before it. Also rewrite the TARHD stuff
because Android (a) doesn't have hd and (b) doesn't have process
substitution in its shell. (I wish I'd noticed TARHD earlier --- I'd
been manually sending the tar files to xxd for debugging instead!)

With this patch, all the tar tests now pass for me on both the device
and host.

1 files changed, 44 insertions, 39 deletions

diff --git a/tests/tar.test b/tests/tar.test
index f1703644..afa35e94 100644
--- a/tests/tar.test
+++ b/tests/tar.test
@@ -16,14 +16,25 @@ LONG=0123456789abcdef0123456789abcdef
 LONG=$LONG$LONG$LONG$LONG$LONG$LONG$LONG$LONG
 LONG=${LONG:1:255}
 
-# Reproducible tarballs: override ownership and timestamp. Also amount of
-# trailing NUL padding varies (1024 bytes is minimum, gnu/dammit does more)
-# so look at first 3 512-byte frames when analyzing header content.
-
+# Reproducible tarballs: override ownership and timestamp.
 TAR='tar c --owner root --group root --mtime @1234567890'
-export BLOCKS=3
-SUM='head -c $(($BLOCKS*512)) | sha1sum | sed "s/ .*//"'
-[ -n "$TARHD" ] && SUM="tee >(hd >&2) | $SUM"
+
+# Also amount of trailing NUL padding varies (1024 bytes is minimum,
+# gnu/dammit does more) so look at first N 512-byte frames when
+# analyzing header content.
+function SUM()
+{
+  if [ -n "$TARHD" ]; then
+    # (Android's shell doesn't support process substitution.)
+    mkfifo xxd-pipe
+    xxd <xxd-pipe & pid=$!
+    tee xxd-pipe | head -c $(($1*512)) | sha1sum | sed "s/ .*//"
+    rm xxd-pipe
+    wait $pid
+  else
+    head -c $(($1*512)) | sha1sum | sed "s/ .*//"
+  fi
+}
 
 function LST()
 {
@@ -31,7 +42,7 @@ function LST()
 }
 
 touch file
-testing "create file" "$TAR file | $SUM" \
+testing "create file" "$TAR file | SUM 3" \
   "fecaecba936e604bb115627a6ef4db7c7a3a8f81\n" "" ""
 
 testing "pass file" "$TAR file | LST" \
@@ -42,7 +53,9 @@ testing "pass file" "$TAR file | LST" \
 skipnot id nobody >/dev/null
 testing "pass user" "tar -c --owner nobody --group root --mtime @0 file | LST" \
   "-rw-rw-r-- nobody/root 0 1970-01-01 00:00 file\n" "" ""
-skipnot grep nobody /etc/group >/dev/null
+# (We assume that if we have the nobody user, we also have the group, in the
+# absence of a good portable way to test for the existence of a named group.)
+skipnot id nobody >/dev/null
 testing "pass group" "tar c --owner root --group nobody --mtime @0 file | LST" \
   "-rw-rw-r-- root/nobody 0 1970-01-01 00:00 file\n" "" ""
 
@@ -56,7 +69,7 @@ testing "adjust mode" \
   "-rwxrwxr-x root/root 0 1987-01-23 12:34:56 file\n" "" ""
 
 mkdir dir
-testing "create dir" "$TAR dir | $SUM" \
+testing "create dir" "$TAR dir | SUM 3" \
   "05739c423d7d4a7f12b3dbb7c94149acb2bb4f8d\n" "" ""
 
 testing "pass dir" "$TAR dir | LST" \
@@ -64,57 +77,57 @@ testing "pass dir" "$TAR dir | LST" \
 
 # note: does _not_ include dir entry in archive, just file
 touch dir/file
-testing "create file in dir" "$TAR dir/file | $SUM" \
+testing "create file in dir" "$TAR dir/file | SUM 3" \
   "2d7b96c7025987215f5a41f10eaa84311160afdb\n" "" ""
 
 # Tests recursion without worrying about content order
-testing "create dir and dir/file" "$TAR dir | $SUM" \
+testing "create dir and dir/file" "$TAR dir | SUM 3" \
   "0bcc8005a3e07eb63c9b735267aecc5b774795d7\n" "" ""
 
 testing "pass dir/file" "$TAR dir | LST" \
   "drwxrwxr-x root/root 0 2009-02-13 23:31 dir/\n-rw-rw-r-- root/root 0 2009-02-13 23:31 dir/file\n" "" ""
 
 echo boing > dir/that
-testing "tar C" "$TAR -C dir that | $SUM" \
+testing "tar C" "$TAR -C dir that | SUM 3" \
   "f0deff71bf4858eb0c5f49d99d052f12f1831feb\n" "" ""
 
 # / and .. only stripped from name, not symlink target.
 ln -s ../name.././.. dir/link
-testing "create symlink" "$TAR dir/link | $SUM" \
+testing "create symlink" "$TAR dir/link | SUM 3" \
   "7324cafbd9aeec5036b6efc54d741f11528aeb10\n" "" ""
 
 # Also two explicit targets
 ln dir/file dir/hardlink
-testing "create hardlink" "$TAR dir/file dir/hardlink | $SUM" \
+testing "create hardlink" "$TAR dir/file dir/hardlink | SUM 3" \
   "c5383651f8c03ec0fe15e8a9e28a4e8e5273990d\n" "" ""
 
 ln dir/link dir/hlink
-testing "create hardlink to symlink" "$TAR dir/link dir/hlink | $SUM" \
+testing "create hardlink to symlink" "$TAR dir/link dir/hlink | SUM 3" \
   "3bc16f8fb6fc8b05f691da8caf989a70ee99284a\n" "" ""
 
 skipnot mkfifo dir/fifo
-testing "create dir/fifo" "$TAR dir/fifo | $SUM" \
+testing "create dir/fifo" "$TAR dir/fifo | SUM 3" \
   "bd1365db6e8ead4c813333f9666994c1899924d9\n" "" ""
 
 # test L and K records
 
 # 4+96=100 (biggest short name), 4+97=101 (shortest long name)
 touch dir/${LONG:1:96} dir/${LONG:1:97}
-testing "create long fname" "$TAR dir/${LONG:1:97} dir/${LONG:1:96} | $SUM" \
+testing "create long fname" "$TAR dir/${LONG:1:97} dir/${LONG:1:96} | SUM 3" \
   "99348686fe9c9bf80f5740f1fc0c6f32f2021e3d\n" "" ""
 
 ln -s dir/${LONG:1:96} dir/lshort
 ln -s dir/${LONG:1:97} dir/llong
-testing "create long symlnk" "$TAR dir/lshort dir/llong | $SUM" \
+testing "create long symlnk" "$TAR dir/lshort dir/llong | SUM 3" \
   "8a5d652dc85f252a2e3b3f47d1ecd699e98a5f4b\n" "" ""
 
 ln -s $LONG dir/${LONG:5}
-BLOCKS=7 testing "create long->long" "$TAR dir/${LONG:5} | $SUM" \
+testing "create long->long" "$TAR dir/${LONG:5} | SUM 7" \
   "543116b8e690a116a559ab5b673f9b6d6601c925\n" "" ""
 # absolute and relative link names, broken and not
 
 ln -s file dir/linkok
-testing "create symlink" "$TAR dir/linkok | $SUM" \
+testing "create symlink" "$TAR dir/linkok | SUM 3" \
   "55652846506cf0a9d43b3ef03ccf9e98123befaf\n" "" ""
 
 ln -s /dev/null dir/linknull
@@ -136,10 +149,6 @@ testing "pass /dev/null" \
   "tar c --mtime @0 /dev/null 2>/dev/null | LST" \
   "crw-rw-rw- root/root 1,3 1970-01-01 00:00 dev/null\n" "" ""
 
-testing "pass /dev/loop0" \
-  "tar c --numeric-owner --mtime @0 /dev/loop0 2>/dev/null | LST" \
-  "brw-rw---- 0/6 7,0 1970-01-01 00:00 dev/loop0\n" "" ""
-
 # compression types
 testing "autodetect gzip" 'LST -f "$FILES"/tar/tar.tgz' \
   "drwxr-x--- enh/eng 0 2017-05-13 01:05 dir/\n-rw-r----- enh/eng 12 2017-05-13 01:05 dir/file\n" \
@@ -150,20 +159,16 @@ testing "manually specify bz2" 'LST -jf "$FILES"/tar/tar.tbz2' \
   "" ""
 
 skipnot mknod dir/char c 12 34
-testing "create dir/char" "tar c dir/char > test.tar && rm -f dir/char && tar xv test.tar && ls -l dir/char" \
-  "a" "" ""
+testing "character special" "tar --mtime @0 -cf test.tar dir/char && rm -f dir/char && tar xf test.tar && ls -l dir/char" \
+  "crw-rw---- 1 root root 12,  34 1970-01-01 00:00 dir/char\n" "" ""
 
-skipnot mknod dir/block c 23 45
-testing "create block" "tar c dir/block > test.tar && rm -f dir/block && tar xv test.tar && ls -l dir/block" \
-  "a" "" ""
-
-skipnot mknod dir/block b 56 78
-testing "create dir/block" "$TAR dir/block | $SUM" \
-  "" "" ""
+skipnot mknod dir/block b 23 45
+testing "block special" "tar --mtime @0 -cf test.tar dir/block && rm -f dir/block && tar xf test.tar && ls -l dir/block" \
+  "brw-rw---- 1 root root 23,  45 1970-01-01 00:00 dir/block\n" "" ""
 
 skipnot chown nobody dir/file
-testing "ownership" "$TAR dir/block | $SUM" \
-  "blat" "" ""
+testing "ownership" "$TAR dir/file | SUM 3" \
+  "2d7b96c7025987215f5a41f10eaa84311160afdb\n" "" ""
 
 mkdir -p dd/sub/blah &&
 tar cf test.tar dd/sub/blah &&
@@ -201,7 +206,7 @@ toyonly testing "cat tbz | extract dir/file (autodetect)" \
   "" ""
 
 yes | (dd bs=$((1<<16)) count=1; dd bs=8192 seek=14 count=1; dd bs=4096 seek=64 count=5) 2>/dev/null > fweep
-testing "sparse without overflow" "$TAR --sparse fweep | $SUM" \
+testing "sparse without overflow" "$TAR --sparse fweep | SUM 3" \
   "e1560110293247934493626d564c8f03c357cec5\n" "" ""
 
 rm fweep
@@ -210,7 +215,7 @@ do
   dd if=/dev/zero of=fweep bs=65536 seek=$i count=1 2>/dev/null
 done
 
-BLOCKS=6 testing "sparse single overflow" "$TAR --sparse fweep | $SUM" \
+testing "sparse single overflow" "$TAR --sparse fweep | SUM 6" \
   "063fc6519ea2607763bc591cc90dd15ac2b43eb8\n" "" ""
 
 rm fweep
@@ -219,7 +224,7 @@ do
   dd if=/dev/zero of=fweep bs=65536 seek=$i count=1 2>/dev/null
 done
 
-BLOCKS=7 testing "sparse double overflow" "$TAR --sparse fweep | $SUM" \
+testing "sparse double overflow" "$TAR --sparse fweep | SUM 7" \
   "f1fe57f8313a9d682ec9013a80f3798910b6ff51\n" "" ""
 
 tar c --sparse fweep > fweep.tar