Fix diff binary file detection

In the process of adding tests for the max file size threshold
(which treats files over a certain size as binary) there seem to
be a number of problems in the new code with detecting binaries.
This should fix those up, as well as add a test for the file
size threshold stuff.

Also, this un-deprecates `GIT_DIFF_LINE_ADD_EOFNL`, since I
finally found a legitimate situation where it would be returned.

1 files changed, 9 insertions, 23 deletions

diff --git a/src/fileops.c b/src/fileops.c
index d4def1a9a..cbe3d4782 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -115,40 +115,26 @@ mode_t git_futils_canonical_mode(mode_t raw_mode)
 		return 0;
 }
 
-#define MAX_READ_STALLS 10
-
 int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
 {
-	int stalls = MAX_READ_STALLS;
+	ssize_t read_size;
 
 	git_buf_clear(buf);
 
 	if (git_buf_grow(buf, len + 1) < 0)
 		return -1;
 
-	buf->ptr[len] = '\0';
-
-	while (len > 0) {
-		ssize_t read_size = p_read(fd, buf->ptr + buf->size, len);
-
-		if (read_size < 0) {
-			giterr_set(GITERR_OS, "Failed to read descriptor");
-			return -1;
-		}
-
-		if (read_size == 0) {
-			stalls--;
+	/* p_read loops internally to read len bytes */
+	read_size = p_read(fd, buf->ptr, len);
 
-			if (!stalls) {
-				giterr_set(GITERR_OS, "Too many stalls reading descriptor");
-				return -1;
-			}
-		}
-
-		len -= read_size;
-		buf->size += read_size;
+	if (read_size < 0) {
+		giterr_set(GITERR_OS, "Failed to read descriptor");
+		return -1;
 	}
 
+	buf->ptr[read_size] = '\0';
+	buf->size = read_size;
+
 	return 0;
 }