[PATCH 2/4] vcs-svn: make buffer_skip_bytes return length read

[Jonathan Nieder <jrnieder@gmail.com>]

Date: Sun, 10 Oct 2010 21:44:21 -0500

Currently there is no way to detect when input ended if it ended
early during buffer_skip_bytes.  Tell the calling program how many
bytes were actually skipped for easier debugging.

Existing callers will still ignore early EOF.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 vcs-svn/line_buffer.c   |   13 +++++++------
 vcs-svn/line_buffer.h   |    2 +-
 vcs-svn/line_buffer.txt |    3 ++-
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/vcs-svn/line_buffer.c b/vcs-svn/line_buffer.c
index 1b5ac8a..58e076f 100644
--- a/vcs-svn/line_buffer.c
+++ b/vcs-svn/line_buffer.c
@@ -86,14 +86,15 @@ void buffer_copy_bytes(uint32_t len)
 	}
 }
 
-void buffer_skip_bytes(uint32_t len)
+uint32_t buffer_skip_bytes(uint32_t nbytes)
 {
-	uint32_t in;
-	while (len > 0 && !feof(infile) && !ferror(infile)) {
-		in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
-		in = fread(byte_buffer, 1, in, infile);
-		len -= in;
+	uint32_t done = 0;
+	while (done < nbytes && !feof(infile) && !ferror(infile)) {
+		uint32_t len = nbytes - done;
+		uint32_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
+		done += fread(byte_buffer, 1, in, infile);
 	}
+	return done;
 }
 
 void buffer_reset(void)
diff --git a/vcs-svn/line_buffer.h b/vcs-svn/line_buffer.h
index 5a19873..b9dd929 100644
--- a/vcs-svn/line_buffer.h
+++ b/vcs-svn/line_buffer.h
@@ -7,7 +7,7 @@ int buffer_ferror(void);
 char *buffer_read_line(void);
 char *buffer_read_string(uint32_t len);
 void buffer_copy_bytes(uint32_t len);
-void buffer_skip_bytes(uint32_t len);
+uint32_t buffer_skip_bytes(uint32_t len);
 void buffer_reset(void);
 
 #endif
diff --git a/vcs-svn/line_buffer.txt b/vcs-svn/line_buffer.txt
index 8906fb1..a08ad8a 100644
--- a/vcs-svn/line_buffer.txt
+++ b/vcs-svn/line_buffer.txt
@@ -52,7 +52,8 @@ Functions
 
 `buffer_skip_bytes`::
 	Discards `len` bytes from the input stream (stopping early
-	if necessary because of an error or eof).
+	if necessary because of an error or eof).  Return value is
+	the number of bytes successfully read.
 
 `buffer_reset`::
 	Deallocates non-static buffers.
-- 
1.7.2.3.554.gc9b5c.dirty