vcs-svn: add binary-safe read function

buffer_read_string works well for non line-oriented input except for
one problem: it does not tell the caller how many bytes were actually
written.  This means that unless one is very careful about checking
for errors (and eof) the calling program cannot tell the difference
between the string "foo" followed by an early end of file and the
string "foo\0bar\0baz".

So introduce a variant that reports the length, too, a thinner wrapper
around strbuf_fread.  Its result is written to a strbuf so the caller
does not need to keep track of the number of bytes read.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/t/t0081-line-buffer.sh b/t/t0081-line-buffer.sh
index 33a728ed9..a8eeb2064 100755
--- a/t/t0081-line-buffer.sh
+++ b/t/t0081-line-buffer.sh
@@ -151,6 +151,15 @@ test_expect_success 'skip, copy null byte' '
 	test_cmp expect actual
 '
 
+test_expect_success 'read null byte' '
+	echo ">QhelloQ" | q_to_nul >expect &&
+	q_to_nul <<-\EOF | test-line-buffer >actual &&
+	binary 8
+	QhelloQ
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'long reads are truncated' '
 	echo foo >expect &&
 	test-line-buffer <<-\EOF >actual &&
@@ -171,4 +180,13 @@ test_expect_success 'long copies are truncated' '
 	test_cmp expect actual
 '
 
+test_expect_success 'long binary reads are truncated' '
+	echo ">foo" >expect &&
+	test-line-buffer <<-\EOF >actual &&
+	binary 5
+	foo
+	EOF
+	test_cmp expect actual
+'
+
 test_done