Add more diff rename detection tests

This adds a bunch more rename detection tests including checks
vs the working directory, the new exact match options, some more
whitespace variants, etc.

This also adds a git_futils_writebuffer helper function and uses
it in checkout.  This is mainly added because I wanted an easy
way to write out a git_buf to disk inside my test code.

3 files changed, 40 insertions, 18 deletions

diff --git a/src/checkout.c b/src/checkout.c
index 5820f626a..c28fcdee0 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -676,33 +676,26 @@ static int buffer_to_file(
 	int file_open_flags,
 	mode_t file_mode)
 {
-	int fd, error;
+	int error;
 
 	if ((error = git_futils_mkpath2file(path, dir_mode)) < 0)
 		return error;
 
-	if ((fd = p_open(path, file_open_flags, file_mode)) < 0) {
-		giterr_set(GITERR_OS, "Could not open '%s' for writing", path);
-		return fd;
-	}
-
-	if ((error = p_write(fd, git_buf_cstr(buffer), git_buf_len(buffer))) < 0) {
-		giterr_set(GITERR_OS, "Could not write to '%s'", path);
-		(void)p_close(fd);
-	} else {
-		if ((error = p_close(fd)) < 0)
-			giterr_set(GITERR_OS, "Error while closing '%s'", path);
+	if ((error = git_futils_writebuffer(
+			buffer, path, file_open_flags, file_mode)) < 0)
+		return error;
 
-		if ((error = p_stat(path, st)) < 0)
-			giterr_set(GITERR_OS, "Error while statting '%s'", path);
+	if (st != NULL && (error = p_stat(path, st)) < 0) {
+		giterr_set(GITERR_OS, "Error while statting '%s'", path);
+		return error;
 	}
 
-	if (!error &&
-		(file_mode & 0100) != 0 &&
-		(error = p_chmod(path, file_mode)) < 0)
+	if ((file_mode & 0100) != 0 && (error = p_chmod(path, file_mode)) < 0) {
 		giterr_set(GITERR_OS, "Failed to set permissions on '%s'", path);
+		return error;
+	}
 
-	return error;
+	return 0;
 }
 
 static int blob_content_to_file(
diff --git a/src/fileops.c b/src/fileops.c
index 98ab8efe3..a3e43214f 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -202,6 +202,32 @@ int git_futils_readbuffer(git_buf *buf, const char *path)
 	return git_futils_readbuffer_updated(buf, path, NULL, NULL, NULL);
 }
 
+int git_futils_writebuffer(
+	const git_buf *buf,	const char *path, int flags, mode_t mode)
+{
+	int fd, error = 0;
+
+	if (flags <= 0)
+		flags = O_CREAT | O_TRUNC | O_WRONLY;
+	if (!mode)
+		mode = GIT_FILEMODE_BLOB;
+
+	if ((fd = p_open(path, flags, mode)) < 0) {
+		giterr_set(GITERR_OS, "Could not open '%s' for writing", path);
+		return fd;
+	}
+
+	if ((error = p_write(fd, git_buf_cstr(buf), git_buf_len(buf))) < 0) {
+		giterr_set(GITERR_OS, "Could not write to '%s'", path);
+		(void)p_close(fd);
+	}
+
+	if ((error = p_close(fd)) < 0)
+		giterr_set(GITERR_OS, "Error while closing '%s'", path);
+
+	return error;
+}
+
 int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode)
 {
 	if (git_futils_mkpath2file(to, dirmode) < 0)
diff --git a/src/fileops.h b/src/fileops.h
index 3e214aab1..f4e059c83 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -22,6 +22,9 @@ extern int git_futils_readbuffer_updated(
 	git_buf *obj, const char *path, time_t *mtime, size_t *size, int *updated);
 extern int git_futils_readbuffer_fd(git_buf *obj, git_file fd, size_t len);
 
+extern int git_futils_writebuffer(
+	const git_buf *buf, const char *path, int open_flags, mode_t mode);
+
 /**
  * File utils
  *