[PATCH v2 08/11] builtin rebase: support --force-rebase

[Pratik Karki via GitGitGadget]

From: Pratik Karki <predatoram...@gmail.com>

In this commit, we add support to `--force-rebase` option. The
equivalent part of the shell script found in `git-legacy-rebase.sh` is
converted as faithfully as possible to C.

The --force-rebase option ensures that the rebase does not simply
fast-forward even if it could.

Signed-off-by: Pratik Karki <predatoram...@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schinde...@gmx.de>
---
 builtin/rebase.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index d67df28efc..8a7bf3d468 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -86,6 +86,7 @@ struct rebase_options {
                REBASE_NO_QUIET = 1<<0,
                REBASE_VERBOSE = 1<<1,
                REBASE_DIFFSTAT = 1<<2,
+               REBASE_FORCE = 1<<3,
        } flags;
        struct strbuf git_am_opt;
 };
@@ -181,6 +182,8 @@ static int run_specific_rebase(struct rebase_options *opts)
                opts->flags & REBASE_VERBOSE ? "t" : "");
        add_var(&script_snippet, "diffstat",
                opts->flags & REBASE_DIFFSTAT ? "t" : "");
+       add_var(&script_snippet, "force_rebase",
+               opts->flags & REBASE_FORCE ? "t" : "");
 
        switch (opts->type) {
        case REBASE_AM:
@@ -409,6 +412,12 @@ int cmd_rebase(int argc, const char **argv, const char 
*prefix)
                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
                        N_("do not show diffstat of what changed upstream"),
                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
+               OPT_BIT('f', "force-rebase", &options.flags,
+                       N_("cherry-pick all commits, even if unchanged"),
+                       REBASE_FORCE),
+               OPT_BIT(0, "no-ff", &options.flags,
+                       N_("cherry-pick all commits, even if unchanged"),
+                       REBASE_FORCE),
                OPT_END(),
        };
 
@@ -551,7 +560,18 @@ int cmd_rebase(int argc, const char **argv, const char 
*prefix)
            !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
                int flag;
 
-               if (!(options.flags & REBASE_NO_QUIET))
+               if (!(options.flags & REBASE_FORCE)) {
+                       if (!(options.flags & REBASE_NO_QUIET))
+                               ; /* be quiet */
+                       else if (!strcmp(branch_name, "HEAD") &&
+                                resolve_ref_unsafe("HEAD", 0, NULL, &flag))
+                               puts(_("HEAD is up to date."));
+                       else
+                               printf(_("Current branch %s is up to date.\n"),
+                                      branch_name);
+                       ret = !!finish_rebase(&options);
+                       goto cleanup;
+               } else if (!(options.flags & REBASE_NO_QUIET))
                        ; /* be quiet */
                else if (!strcmp(branch_name, "HEAD") &&
                         resolve_ref_unsafe("HEAD", 0, NULL, &flag))
-- 
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