Re: [TIG PATCH] Improve parent blame to detect renames by using the previous information

[Jonas Fonseca <fonseca@diku.dk>]

Sorry, forgot to prefix this mail properly ...

On Sat, Jun 5, 2010 at 15:56, Jonas Fonseca <fonseca@diku.dk> wrote:
> From git commit 96e117099c0e4f7d508eb071f60b6275038f6f37:
>
>  It gives the parent commit of the blamed commit, _and_ a path in that
>  parent commit that corresponds to the blamed path --- in short, it is
>  the origin that would have been blamed (or passed blame through) for
>  the line _if_ the blamed commit did not change that line.
>
> This functionality was released in git version 1.6.3 in 2009-05-06.
> ---
>  NEWS  |    2 +
>  tig.c |   99 +++++++++++++++-------------------------------------------------
>  2 files changed, 25 insertions(+), 76 deletions(-)
>
>  I finally got some more time to dig around this. What if we simply uses
>  the information given by the porcelain output's previous line? It
>  handles your simple test case, and navigating in the tig repository. It
>  also makes it possible to delete a lot of code.
>
> diff --git a/NEWS b/NEWS
> index 190e5dc..499bdbc 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -38,6 +38,8 @@ Bug fixes:
>  - Fix unbind to behave as if the keybinding was never defined.
>  - Fix unbind to also cover built-in run requests.
>  - Fix parsing of unknown keymap names.
> + - Blame view: fix parent blame to detect renames. It uses "previous"
> +   line info from the blame porcelain output added in git version 1.6.3.
>
>  tig-0.15
>  --------
> diff --git a/tig.c b/tig.c
> index 01f48c3..044da28 100644
> --- a/tig.c
> +++ b/tig.c
> @@ -3977,73 +3977,6 @@ parse_author_line(char *ident, const char **author, struct time *time)
>        }
>  }
>
> -static bool
> -open_commit_parent_menu(char buf[SIZEOF_STR], int *parents)
> -{
> -       char rev[SIZEOF_REV];
> -       const char *revlist_argv[] = {
> -               "git", "log", "--no-color", "-1", "--pretty=format:%s", rev, NULL
> -       };
> -       struct menu_item *items;
> -       char text[SIZEOF_STR];
> -       bool ok = TRUE;
> -       int i;
> -
> -       items = calloc(*parents + 1, sizeof(*items));
> -       if (!items)
> -               return FALSE;
> -
> -       for (i = 0; i < *parents; i++) {
> -               string_copy_rev(rev, &buf[SIZEOF_REV * i]);
> -               if (!io_run_buf(revlist_argv, text, sizeof(text)) ||
> -                   !(items[i].text = strdup(text))) {
> -                       ok = FALSE;
> -                       break;
> -               }
> -       }
> -
> -       if (ok) {
> -               *parents = 0;
> -               ok = prompt_menu("Select parent", items, parents);
> -       }
> -       for (i = 0; items[i].text; i++)
> -               free((char *) items[i].text);
> -       free(items);
> -       return ok;
> -}
> -
> -static bool
> -select_commit_parent(const char *id, char rev[SIZEOF_REV], const char *path)
> -{
> -       char buf[SIZEOF_STR * 4];
> -       const char *revlist_argv[] = {
> -               "git", "log", "--no-color", "-1",
> -                       "--pretty=format:%P", id, "--", path, NULL
> -       };
> -       int parents;
> -
> -       if (!io_run_buf(revlist_argv, buf, sizeof(buf)) ||
> -           (parents = strlen(buf) / 40) < 0) {
> -               report("Failed to get parent information");
> -               return FALSE;
> -
> -       } else if (parents == 0) {
> -               if (path)
> -                       report("Path '%s' does not exist in the parent", path);
> -               else
> -                       report("The selected commit has no parents");
> -               return FALSE;
> -       }
> -
> -       if (parents == 1)
> -               parents = 0;
> -       else if (!open_commit_parent_menu(buf, &parents))
> -               return FALSE;
> -
> -       string_copy_rev(rev, &buf[41 * parents]);
> -       return TRUE;
> -}
> -
>  /*
>  * Pager backend
>  */
> @@ -4898,7 +4831,8 @@ struct blame_commit {
>        const char *author;             /* Author of the commit. */
>        struct time time;               /* Date from the author ident. */
>        char filename[128];             /* Name of file. */
> -       bool has_previous;              /* Was a "previous" line detected. */
> +       char parent_id[SIZEOF_REV];     /* Parent/previous SHA1 ID. */
> +       char parent_filename[128];      /* Parent/previous name of file. */
>  };
>
>  struct blame {
> @@ -5097,7 +5031,11 @@ blame_read(struct view *view, char *line)
>                string_ncopy(commit->title, line, strlen(line));
>
>        } else if (match_blame_header("previous ", &line)) {
> -               commit->has_previous = TRUE;
> +               if (strlen(line) <= SIZEOF_REV)
> +                       return FALSE;
> +               string_copy_rev(commit->parent_id, line);
> +               line += SIZEOF_REV;
> +               string_ncopy(commit->parent_filename, line, strlen(line));
>
>        } else if (match_blame_header("filename ", &line)) {
>                string_ncopy(commit->filename, line, strlen(line));
> @@ -5153,15 +5091,21 @@ 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;
>
> +       snprintf(from, sizeof(from), "%s:%s", opt_ref, opt_file);
> +       snprintf(to, sizeof(to), "%s:%s", blame->commit->id,
> +                blame->commit->filename);
> +
>        if (!io_run(&io, IO_RD, NULL, diff_tree_argv))
>                return;
>
> @@ -5204,10 +5148,13 @@ blame_request(struct view *view, enum request request, struct line *line)
>                break;
>
>        case REQ_PARENT:
> -               if (check_blame_commit(blame, TRUE) &&
> -                   select_commit_parent(blame->commit->id, opt_ref,
> -                                        blame->commit->filename)) {
> -                       string_copy(opt_file, blame->commit->filename);
> +               if (!check_blame_commit(blame, TRUE))
> +                       break;
> +               if (!*blame->commit->parent_id) {
> +                       report("The selected commit has no parents");
> +               } else {
> +                       string_copy_rev(opt_ref, blame->commit->parent_id);
> +                       string_copy_rev(opt_file, blame->commit->parent_filename);
>                        setup_blame_parent_line(view, blame);
>                        open_view(view, REQ_VIEW_BLAME, OPEN_REFRESH);
>                }
> @@ -5228,7 +5175,7 @@ blame_request(struct view *view, enum request request, struct line *line)
>                                        "-C", "-M", "HEAD", "--", view->vid, NULL
>                        };
>
> -                       if (!blame->commit->has_previous) {
> +                       if (!*blame->commit->parent_id) {
>                                diff_index_argv[1] = "diff";
>                                diff_index_argv[2] = "--no-color";
>                                diff_index_argv[6] = "--";
> --
> 1.7.1.354.ge64bd
>
>



-- 
Jonas Fonseca