Improve parent blame to handle line-jumping for renames better

... by using git diff to compare directly the current and parent blob.

Signed-off-by: Jonas Fonseca <fonseca@diku.dk>

diff --git a/tig.c b/tig.c
index c2417bfee168eb4b52c6287ee01bcc524a9bc635..dd155e35e23a6b11fd3aedc9e5883085372ebdb7 100644 (file)
--- a/tig.c
+++ b/tig.c
@@ -5110,16 +5110,20 @@ check_blame_commit(struct blame *blame, bool check_null_id)
 static void
 setup_blame_parent_line(struct view *view, struct blame *blame)
 {
+       char from[SIZEOF_REF + SIZEOF_STR];
+       char to[SIZEOF_REF + SIZEOF_STR];
        const char *diff_tree_argv[] = {
-               "git", "diff-tree", "-U0", blame->commit->id,
-                       "--", blame->commit->filename, NULL
+               "git", "diff", "--no-textconv", "--no-extdiff", "--no-color",
+                       "-U0", from, to, "--", NULL
        };
        struct io io;
        int parent_lineno = -1;
        int blamed_lineno = -1;
        char *line;
 
-       if (!io_run(&io, IO_RD, NULL, diff_tree_argv))
+       if (!string_format(from, "%s:%s", opt_ref, opt_file) ||
+           !string_format(to, "%s:%s", blame->commit->id, blame->commit->filename) ||
+           !io_run(&io, IO_RD, NULL, diff_tree_argv))
                return;
 
        while ((line = io_get(&io, '\n', TRUE))) {