tutorial: use "project history" instead of "changelog" in header

diff --git a/csum-file.c b/csum-file.c
index b7174c6c056c5a8f2a800ecbcb3cdf304c0bfc3f..7c806ada48d0fd58c091f9415fc8bb2f61bdd2e6 100644 (file)
--- a/csum-file.c
+++ b/csum-file.c
@@ -49,6 +49,8 @@ int sha1close(struct sha1file *f, unsigned char *result, int update)
 
 int sha1write(struct sha1file *f, void *buf, unsigned int count)
 {
+       if (f->do_crc)
+               f->crc32 = crc32(f->crc32, buf, count);
        while (count) {
                unsigned offset = f->offset;
                unsigned left = sizeof(f->buffer) - offset;
@@ -91,6 +93,7 @@ struct sha1file *sha1create(const char *fmt, ...)
        f->fd = fd;
        f->error = 0;
        f->offset = 0;
+       f->do_crc = 0;
        SHA1_Init(&f->ctx);
        return f;
 }
@@ -111,6 +114,7 @@ struct sha1file *sha1fd(int fd, const char *name)
        f->fd = fd;
        f->error = 0;
        f->offset = 0;
+       f->do_crc = 0;
        SHA1_Init(&f->ctx);
        return f;
 }
@@ -143,4 +147,14 @@ int sha1write_compressed(struct sha1file *f, void *in, unsigned int size)
        return size;
 }
 
+void crc32_begin(struct sha1file *f)
+{
+       f->crc32 = crc32(0, Z_NULL, 0);
+       f->do_crc = 1;
+}
 
+uint32_t crc32_end(struct sha1file *f)
+{
+       f->do_crc = 0;
+       return f->crc32;
+}