t9300: use perl "head -c" clone in place of "dd bs=1 count=16000" kluge

It is unfortunate to have to issue thousands of one-byte read calls to
work around dd's refusal to buffer input that would fill a block after
a short read (a3a6f4, 2010-12-13).  We could do better by using
"head -c", if it were available on all platforms we cared about.
Replace it with some simple perl.

While doing so, restructure 9300.114 to use a subshell instead of a
script.  Subshells can inherit functions (like the new head_c) from
the parent shell while external scripts cannot.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 5a1925f690fe309436a06534addf26a30bc10e1f..222d1059ef99879d3db387be798f973fb093f53e 100755 (executable)
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -7,6 +7,23 @@ test_description='test git fast-import utility'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
 
+# Print $1 bytes from stdin to stdout.
+#
+# This could be written as "head -c $1", but IRIX "head" does not
+# support the -c option.
+head_c () {
+       perl -e '
+               my $len = $ARGV[1];
+               while ($len > 0) {
+                       my $s;
+                       my $nread = sysread(STDIN, $s, $len);
+                       die "cannot read: $!" unless defined($nread);
+                       print $s;
+                       $len -= $nread;
+               }
+       ' - "$1"
+}
+
 file2_data='file2
 second line of EOF'
 
@@ -1888,44 +1905,41 @@ test_expect_success PIPE 'R: copy using cat-file' '
        rm -f blobs &&
        cat >frontend <<-\FRONTEND_END &&
        #!/bin/sh
-       cat <<EOF &&
-       feature cat-blob
-       blob
-       mark :1
-       data <<BLOB
-       EOF
-       cat big
-       cat <<EOF
-       BLOB
-       cat-blob :1
-       EOF
-
-       read blob_id type size <&3 &&
-       echo "$blob_id $type $size" >response &&
-       dd of=blob bs=1 count=$size <&3 &&
-       read newline <&3 &&
-
-       cat <<EOF &&
-       commit refs/heads/copied
-       committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
-       data <<COMMIT
-       copy big file as file3
-       COMMIT
-       M 644 inline file3
-       data <<BLOB
-       EOF
-       cat blob &&
-       cat <<EOF
-       BLOB
-       EOF
        FRONTEND_END
 
        mkfifo blobs &&
        (
                export GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE &&
-               sh frontend 3<blobs |
-               git fast-import --cat-blob-fd=3 3>blobs
-       ) &&
+               cat <<-\EOF &&
+               feature cat-blob
+               blob
+               mark :1
+               data <<BLOB
+               EOF
+               cat big &&
+               cat <<-\EOF &&
+               BLOB
+               cat-blob :1
+               EOF
+
+               read blob_id type size <&3 &&
+               echo "$blob_id $type $size" >response &&
+               head_c $size >blob <&3 &&
+               read newline <&3 &&
+
+               cat <<-EOF &&
+               commit refs/heads/copied
+               committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+               data <<COMMIT
+               copy big file as file3
+               COMMIT
+               M 644 inline file3
+               data <<BLOB
+               EOF
+               cat blob &&
+               echo BLOB
+       ) 3<blobs |
+       git fast-import --cat-blob-fd=3 3>blobs &&
        git show copied:file3 >actual &&
        test_cmp expect.response response &&
        test_cmp big actual
@@ -1953,7 +1967,7 @@ test_expect_success PIPE 'R: print blob mid-commit' '
                EOF
 
                read blob_id type size <&3 &&
-               dd of=actual bs=1 count=$size <&3 &&
+               head_c $size >actual <&3 &&
                read newline <&3 &&
 
                echo
@@ -1988,7 +2002,7 @@ test_expect_success PIPE 'R: print staged blob within commit' '
                echo "cat-blob $to_get" &&
 
                read blob_id type size <&3 &&
-               dd of=actual bs=1 count=$size <&3 &&
+               head_c $size >actual <&3 &&
                read newline <&3 &&
 
                echo deleteall