Add more buf_append_base64() tests... and fix it.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/tests/buftest.c b/tests/buftest.c
index a15cb2ef8c305025fe97bc264c6a4b5476ee8394..25bd20f799e6544f994f4d1637afa5b10feefe7c 100644 (file)
--- a/tests/buftest.c
+++ b/tests/buftest.c
@@ -101,6 +101,7 @@ struct oc_text_buf {
        int error;
 };
 
+#define BUFTEST
 #include "../textbuf.c"
 
 #define assert(x) if (!(x)) {                                          \
@@ -133,6 +134,20 @@ int main(void)
        buf_append_base64(buf, testbytes, -1, 0);
        assert(buf_error(buf) == -EINVAL);
 
+       buf->error = 0;
+       buf_truncate(buf);
+
+       int ll;
+
+       for (ll = 0; ll < 128; ll += 4) {
+               for (len = 0; len < 16384; len++) {
+                       buf_truncate(buf);
+                       buf_append_base64(buf, testbytes, len, ll);
+                       assert(!buf_error(buf));
+                       if (len > 128)
+                               len += len/2;
+               }
+       }
        buf_free(buf);
        return 0;
 }

diff --git a/textbuf.c b/textbuf.c
index a8b22a48dbbbeeb3b623112dc27b54ce13f959f8..05d0bcc2e8799df67c20366d3476483f3436a360 100644 (file)
--- a/textbuf.c
+++ b/textbuf.c
@@ -418,14 +418,17 @@ void buf_append_base64(struct oc_text_buf *buf, const void *bytes, int len,
        if (!buf || buf->error)
                return;
 
-       if (len < 0 || line_len < 0 || (line_len % 3)) {
+       if (len < 0 || line_len < 0 || (line_len & 3)) {
                buf->error = -EINVAL;
                return;
        }
 
-       unsigned int needed = ((len + 2u) / 3) * 4 + 1;
-       if (line_len)
-               needed += needed / line_len;
+       unsigned int needed = ((len + 2u) / 3) * 4;
+
+       /* Line endings, but not for the last line if it reaches line_len */
+       if (line_len && needed)
+               needed += (needed - 1) / line_len;
+       needed++; /* Allow for the trailing NUL */
 
        if (needed >= (unsigned)(OC_BUF_MAX - buf->pos)) {
                buf->error = -E2BIG;
@@ -435,6 +438,9 @@ void buf_append_base64(struct oc_text_buf *buf, const void *bytes, int len,
        if (buf_ensure_space(buf, needed))
                return;
 
+#ifdef BUFTEST
+       int orig_len = len, orig_pos = buf->pos;
+#endif
        int ll = 0;
        while (len > 0) {
                if (line_len) {
@@ -465,5 +471,12 @@ void buf_append_base64(struct oc_text_buf *buf, const void *bytes, int len,
                in += 3;
                len -= 3;
        }
+#ifdef BUFTEST
+       if (buf->pos != orig_pos + needed - 1) {
+               printf("Used %d instead of calculated %d for %d bytes at line len %d\n",
+                      buf->pos - orig_pos, needed, orig_len, line_len);
+               buf->error = -EIO;
+       }
+#endif
        buf->data[buf->pos] = 0;
 }