From c6b08d222fd62ac05657a77898e1d749dc3be72f Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sat, 26 Oct 2019 16:41:46 +0200
Subject: stream: stop accessing buffer internals in stream_read_line()

Getting this out of the way in preparation for reworking stream
internals.
---
 stream/stream.c | 23 +++++++++++++++--------
 stream/stream.h |  1 +
 2 files changed, 16 insertions(+), 8 deletions(-)

(limited to 'stream')

diff --git a/stream/stream.c b/stream/stream.c
index 36b08803b3..6dfbfa31a7 100644
--- a/stream/stream.c
+++ b/stream/stream.c
@@ -496,6 +496,16 @@ struct bstr stream_peek(stream_t *s, int len)
     return (bstr){.start = &s->buffer[s->buf_pos], .len = MPMIN(len, avail)};
 }
 
+// Peek the current buffer. This will return at least 1 byte, unless EOF was
+// reached. If data is returned, the length is essentially random.
+struct bstr stream_peek_buffer(stream_t *s)
+{
+    if (s->buf_len - s->buf_pos < 1)
+        stream_fill_buffer(s);
+    return (bstr){.start = &s->buffer[s->buf_pos],
+                  .len = s->buf_len - s->buf_pos};
+}
+
 int stream_write_buffer(stream_t *s, unsigned char *buf, int len)
 {
     if (!s->write_buffer)
@@ -676,16 +686,13 @@ static int read_characters(stream_t *s, uint8_t *dst, int dstsize, int utf16)
         }
         return cur - dst;
     } else {
-        if (s->buf_pos >= s->buf_len)
-            stream_fill_buffer(s);
-        uint8_t *src = s->buffer + s->buf_pos;
-        int src_len = s->buf_len - s->buf_pos;
-        uint8_t *end = memchr(src, '\n', src_len);
-        int len = end ? end - src + 1 : src_len;
+        bstr buf = stream_peek_buffer(s);
+        uint8_t *end = memchr(buf.start, '\n', buf.len);
+        int len = end ? end - buf.start + 1 : buf.len;
         if (len > dstsize)
             return -1; // line too long
-        memcpy(dst, src, len);
-        s->buf_pos += len;
+        memcpy(dst, buf.start, len);
+        stream_skip(s, len);
         return len;
     }
 }
diff --git a/stream/stream.h b/stream/stream.h
index dcea82dace..71a7011fef 100644
--- a/stream/stream.h
+++ b/stream/stream.h
@@ -180,6 +180,7 @@ bool stream_seek(stream_t *s, int64_t pos);
 int stream_read(stream_t *s, char *mem, int total);
 int stream_read_partial(stream_t *s, char *buf, int buf_size);
 struct bstr stream_peek(stream_t *s, int len);
+struct bstr stream_peek_buffer(stream_t *s);
 void stream_drop_buffers(stream_t *s);
 int64_t stream_get_size(stream_t *s);
 
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