From 5717b50f2f80e581c90dcca854f42eff0a3afbcd Mon Sep 17 00:00:00 2001
From: 4kills <dominik.ochs@gmx.net>
Date: Fri, 19 Jan 2024 09:46:51 +0100
Subject: [PATCH] fix: now working with too small buffers

---
 reader.go      | 15 ++-------------
 reader_test.go | 42 ++++++++++++++++++++++++++++++++++--------
 2 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/reader.go b/reader.go
index d15b280..92809f8 100644
--- a/reader.go
+++ b/reader.go
@@ -60,18 +60,7 @@ func (r *Reader) Read(p []byte) (int, error) {
 	}
 
 	if r.outBuffer.Len() != 0 {
-		min := len(p)
-		if len(p) < r.outBuffer.Len() {
-			min = r.outBuffer.Len()
-		}
-		copy(p, r.outBuffer.Bytes()[:min])
-		r.outBuffer.Next(min)
-
-		var err error
-		if r.outBuffer.Len() == 0 && r.eof {
-			err = io.EOF
-		}
-		return min, err
+		return r.outBuffer.Read(p)
 	}
 
 	n, err := r.r.Read(p)
@@ -87,7 +76,7 @@ func (r *Reader) Read(p []byte) (int, error) {
 	}
 	r.inBuffer.Next(processed)
 
-	if r.eof && len(out) <= len(p){
+	if r.eof && len(out) <= len(p) {
 		copy(p, out)
 		return len(out), io.EOF
 	}
diff --git a/reader_test.go b/reader_test.go
index ef05c89..da14d06 100644
--- a/reader_test.go
+++ b/reader_test.go
@@ -29,7 +29,7 @@ func TestReadBytes(t *testing.T) {
 	sliceEquals(t, longString, act)
 }
 
-func TestRead_SufficientBuffer(t *testing.T) {
+func initTestRead(t *testing.T, bufferSize int) (*bytes.Buffer, *zlib.Writer, *Reader, func(r *Reader) error) {
 	b := &bytes.Buffer{}
 	out := &bytes.Buffer{}
 	w := zlib.NewWriter(b)
@@ -39,27 +39,53 @@ func TestRead_SufficientBuffer(t *testing.T) {
 		t.Error(err)
 		t.FailNow()
 	}
-	defer r.Close()
 
-	read := func() {
-		p := make([]byte, 1e+4)
+	read := func(r *Reader) error {
+		p := make([]byte, bufferSize)
 		n, err := r.Read(p)
 		if err != nil && err != io.EOF {
 			t.Error(err)
 			t.Error(n)
+			t.FailNow()
 		}
 		out.Write(p[:n])
+		return err // io.EOF or nil
 	}
 
-	_, err = w.Write(shortString)
+	return out, w, r, read
+}
+
+func TestRead_SufficientBuffer(t *testing.T) {
+	out, w, r, read := initTestRead(t, 1e+4)
+	defer r.Close()
+
+	w.Write(shortString)
 	w.Flush()
 
-	read()
+	read(r)
 
-	_, err = w.Write(shortString)
+	w.Write(shortString)
 	w.Close()
 
-	read()
+	read(r)
+
+	sliceEquals(t, append(shortString, shortString...), out.Bytes())
+}
+
+func TestRead_SmallBuffer(t *testing.T) {
+	out, w, r, read := initTestRead(t, 1)
+	defer r.Close()
+
+	w.Write(shortString)
+	w.Write(shortString)
+	w.Close()
+
+	for {
+		err := read(r)
+		if err == io.EOF {
+			break
+		}
+	}
 
 	sliceEquals(t, append(shortString, shortString...), out.Bytes())
 }