built-in add -i: start implementing the `patch` functionality in C
In the previous steps, we re-implemented the main loop of `git add -i` in C, and most of the commands. Notably, we left out the actual functionality of `patch`, as the relevant code makes up more than half of `git-add--interactive.perl`, and is actually pretty independent of the rest of the commands. With this commit, we start to tackle that `patch` part. For better separation of concerns, we keep the code in a separate file, `add-patch.c`. The new code is still guarded behind the `add.interactive.useBuiltin` config setting, and for the moment, it can only be called via `git add -p`. The actual functionality follows the original implementation of 5cde71d64aff (git-add --interactive, 2006-12-10), but not too closely (for example, we use string offsets rather than copying strings around, and after seeing whether the `k` and `j` commands are applicable, in the C version we remember which previous/next hunk was undecided, and use it rather than looking again when the user asked to jump). As a further deviation from that commit, We also use a comma instead of a slash to separate the available commands in the prompt, as the current version of the Perl script does this, and we also add a line about the question mark ("print help") to the help text. While it is tempting to use this conversion of `git add -p` as an excuse to work on `apply_all_patches()` so that it does _not_ want to read a file from `stdin` or from a file, but accepts, say, an `strbuf` instead, we will refrain from this particular rabbit hole at this stage. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Johannes Schindelin committed
Dec 13, 2019 at 08:07 UTC
f6aa7ecc34373f32621b05659d5d2447d690be18
4 files changed
+277
-5
Makefile
+1
@@ -824,6 +824,7 @@ LIB_H := $(sort $(patsubst ./%,%,$(shell git ls-files '*.h' ':!t/' ':!Documentat
824
825
LIB_OBJS += abspath.o
826
LIB_OBJS += add-interactive.o
827
+LIB_OBJS += add-patch.o
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LIB_OBJS += advice.o
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LIB_OBJS += alias.o
830
LIB_OBJS += alloc.o
add-interactive.h
+1
@@ -4,5 +4,6 @@
4
struct repository;
5
struct pathspec;
6
int run_add_i(struct repository *r, const struct pathspec *ps);
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+int run_add_p(struct repository *r, const struct pathspec *ps);
8
9
#endif
add-patch.c
new
+265
@@ -0,0 +1,265 @@
1
+#include "cache.h"
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+#include "add-interactive.h"
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+#include "strbuf.h"
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+#include "run-command.h"
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+#include "argv-array.h"
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+#include "pathspec.h"
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+
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+struct hunk {
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+ size_t start, end;
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+ enum { UNDECIDED_HUNK = 0, SKIP_HUNK, USE_HUNK } use;
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+};
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+
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+struct add_p_state {
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+ struct repository *r;
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+ struct strbuf answer, buf;
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+
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+ /* parsed diff */
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+ struct strbuf plain;
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+ struct hunk head;
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+ struct hunk *hunk;
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+ size_t hunk_nr, hunk_alloc;
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+};
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+
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+static void setup_child_process(struct add_p_state *s,
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+ struct child_process *cp, ...)
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+{
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+ va_list ap;
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+ const char *arg;
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+
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+ va_start(ap, cp);
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+ while ((arg = va_arg(ap, const char *)))
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+ argv_array_push(&cp->args, arg);
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+ va_end(ap);
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+
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+ cp->git_cmd = 1;
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+ argv_array_pushf(&cp->env_array,
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+ INDEX_ENVIRONMENT "=%s", s->r->index_file);
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+}
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+
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+static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
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+{
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+ struct strbuf *plain = &s->plain;
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+ struct child_process cp = CHILD_PROCESS_INIT;
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+ char *p, *pend;
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+ size_t i;
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+ struct hunk *hunk = NULL;
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+ int res;
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+
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+ /* Use `--no-color` explicitly, just in case `diff.color = always`. */
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+ setup_child_process(s, &cp,
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+ "diff-files", "-p", "--no-color", "--", NULL);
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+ for (i = 0; i < ps->nr; i++)
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+ argv_array_push(&cp.args, ps->items[i].original);
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+
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+ res = capture_command(&cp, plain, 0);
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+ if (res)
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+ return error(_("could not parse diff"));
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+ if (!plain->len)
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+ return 0;
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+ strbuf_complete_line(plain);
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+
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+ /* parse hunks */
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+ p = plain->buf;
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+ pend = p + plain->len;
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+ while (p != pend) {
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+ char *eol = memchr(p, '\n', pend - p);
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+ if (!eol)
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+ eol = pend;
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+
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+ if (starts_with(p, "diff ")) {
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+ if (p != plain->buf)
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+ BUG("multi-file diff not yet handled");
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+ hunk = &s->head;
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+ } else if (p == plain->buf)
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+ BUG("diff starts with unexpected line:\n"
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+ "%.*s\n", (int)(eol - p), p);
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+ else if (starts_with(p, "@@ ")) {
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+ s->hunk_nr++;
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+ ALLOC_GROW(s->hunk, s->hunk_nr,
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+ s->hunk_alloc);
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+ hunk = s->hunk + s->hunk_nr - 1;
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+ memset(hunk, 0, sizeof(*hunk));
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+
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+ hunk->start = p - plain->buf;
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+ }
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+
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+ p = eol == pend ? pend : eol + 1;
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+ hunk->end = p - plain->buf;
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+ }
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+
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+ return 0;
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+}
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+
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+static void render_hunk(struct add_p_state *s, struct hunk *hunk,
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+ struct strbuf *out)
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+{
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+ strbuf_add(out, s->plain.buf + hunk->start,
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+ hunk->end - hunk->start);
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+}
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+
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+static void reassemble_patch(struct add_p_state *s, struct strbuf *out)
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+{
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+ struct hunk *hunk;
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+ size_t i;
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+
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+ render_hunk(s, &s->head, out);
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+
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+ for (i = 0; i < s->hunk_nr; i++) {
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+ hunk = s->hunk + i;
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+ if (hunk->use == USE_HUNK)
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+ render_hunk(s, hunk, out);
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+ }
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+}
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+
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+static const char help_patch_text[] =
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+N_("y - stage this hunk\n"
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+ "n - do not stage this hunk\n"
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+ "a - stage this and all the remaining hunks\n"
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+ "d - do not stage this hunk nor any of the remaining hunks\n"
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+ "j - leave this hunk undecided, see next undecided hunk\n"
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+ "J - leave this hunk undecided, see next hunk\n"
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+ "k - leave this hunk undecided, see previous undecided hunk\n"
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+ "K - leave this hunk undecided, see previous hunk\n"
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+ "? - print help\n");
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+
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+static int patch_update_file(struct add_p_state *s)
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+{
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+ size_t hunk_index = 0;
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+ ssize_t i, undecided_previous, undecided_next;
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+ struct hunk *hunk;
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+ char ch;
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+ struct child_process cp = CHILD_PROCESS_INIT;
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+
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+ if (!s->hunk_nr)
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+ return 0;
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+
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+ strbuf_reset(&s->buf);
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+ render_hunk(s, &s->head, &s->buf);
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+ fputs(s->buf.buf, stdout);
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+ for (;;) {
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+ if (hunk_index >= s->hunk_nr)
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+ hunk_index = 0;
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+ hunk = s->hunk + hunk_index;
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+
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+ undecided_previous = -1;
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+ for (i = hunk_index - 1; i >= 0; i--)
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+ if (s->hunk[i].use == UNDECIDED_HUNK) {
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+ undecided_previous = i;
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+ break;
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+ }
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+
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+ undecided_next = -1;
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+ for (i = hunk_index + 1; i < s->hunk_nr; i++)
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+ if (s->hunk[i].use == UNDECIDED_HUNK) {
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+ undecided_next = i;
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+ break;
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+ }
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+
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+ /* Everything decided? */
160
+ if (undecided_previous < 0 && undecided_next < 0 &&
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+ hunk->use != UNDECIDED_HUNK)
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+ break;
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+
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+ strbuf_reset(&s->buf);
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+ render_hunk(s, hunk, &s->buf);
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+ fputs(s->buf.buf, stdout);
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+
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+ strbuf_reset(&s->buf);
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+ if (undecided_previous >= 0)
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+ strbuf_addstr(&s->buf, ",k");
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+ if (hunk_index)
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+ strbuf_addstr(&s->buf, ",K");
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+ if (undecided_next >= 0)
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+ strbuf_addstr(&s->buf, ",j");
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+ if (hunk_index + 1 < s->hunk_nr)
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+ strbuf_addstr(&s->buf, ",J");
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+ printf("(%"PRIuMAX"/%"PRIuMAX") ",
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+ (uintmax_t)hunk_index + 1, (uintmax_t)s->hunk_nr);
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+ printf(_("Stage this hunk [y,n,a,d%s,?]? "), s->buf.buf);
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+ fflush(stdout);
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+ if (strbuf_getline(&s->answer, stdin) == EOF)
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+ break;
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+ strbuf_trim_trailing_newline(&s->answer);
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+
185
+ if (!s->answer.len)
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+ continue;
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+ ch = tolower(s->answer.buf[0]);
188
+ if (ch == 'y') {
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+ hunk->use = USE_HUNK;
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+soft_increment:
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+ hunk_index = undecided_next < 0 ?
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+ s->hunk_nr : undecided_next;
193
+ } else if (ch == 'n') {
194
+ hunk->use = SKIP_HUNK;
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+ goto soft_increment;
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+ } else if (ch == 'a') {
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+ for (; hunk_index < s->hunk_nr; hunk_index++) {
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+ hunk = s->hunk + hunk_index;
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+ if (hunk->use == UNDECIDED_HUNK)
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+ hunk->use = USE_HUNK;
201
+ }
202
+ } else if (ch == 'd') {
203
+ for (; hunk_index < s->hunk_nr; hunk_index++) {
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+ hunk = s->hunk + hunk_index;
205
+ if (hunk->use == UNDECIDED_HUNK)
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+ hunk->use = SKIP_HUNK;
207
+ }
208
+ } else if (hunk_index && s->answer.buf[0] == 'K')
209
+ hunk_index--;
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+ else if (hunk_index + 1 < s->hunk_nr &&
211
+ s->answer.buf[0] == 'J')
212
+ hunk_index++;
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+ else if (undecided_previous >= 0 &&
214
+ s->answer.buf[0] == 'k')
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+ hunk_index = undecided_previous;
216
+ else if (undecided_next >= 0 && s->answer.buf[0] == 'j')
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+ hunk_index = undecided_next;
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+ else
219
+ puts(_(help_patch_text));
220
+ }
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+
222
+ /* Any hunk to be used? */
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+ for (i = 0; i < s->hunk_nr; i++)
224
+ if (s->hunk[i].use == USE_HUNK)
225
+ break;
226
+
227
+ if (i < s->hunk_nr) {
228
+ /* At least one hunk selected: apply */
229
+ strbuf_reset(&s->buf);
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+ reassemble_patch(s, &s->buf);
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+
232
+ discard_index(s->r->index);
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+ setup_child_process(s, &cp, "apply", "--cached", NULL);
234
+ if (pipe_command(&cp, s->buf.buf, s->buf.len,
235
+ NULL, 0, NULL, 0))
236
+ error(_("'git apply --cached' failed"));
237
+ if (!repo_read_index(s->r))
238
+ repo_refresh_and_write_index(s->r, REFRESH_QUIET, 0,
239
+ 1, NULL, NULL, NULL);
240
+ }
241
+
242
+ putchar('\n');
243
+ return 0;
244
+}
245
+
246
+int run_add_p(struct repository *r, const struct pathspec *ps)
247
+{
248
+ struct add_p_state s = { r, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT };
249
+
250
+ if (discard_index(r->index) < 0 || repo_read_index(r) < 0 ||
251
+ repo_refresh_and_write_index(r, REFRESH_QUIET, 0, 1,
252
+ NULL, NULL, NULL) < 0 ||
253
+ parse_diff(&s, ps) < 0) {
254
+ strbuf_release(&s.plain);
255
+ return -1;
256
+ }
257
+
258
+ if (s.hunk_nr)
259
+ patch_update_file(&s);
260
+
261
+ strbuf_release(&s.answer);
262
+ strbuf_release(&s.buf);
263
+ strbuf_release(&s.plain);
264
+ return 0;
265
+}
builtin/add.c
+10
-5
@@ -189,12 +189,17 @@ int run_add_interactive(const char *revision, const char *patch_mode,
189
int use_builtin_add_i =
190
git_env_bool("GIT_TEST_ADD_I_USE_BUILTIN", -1);
191
192
- if (!patch_mode) {
193
- if (use_builtin_add_i < 0)
194
- git_config_get_bool("add.interactive.usebuiltin",
195
- &use_builtin_add_i);
196
- if (use_builtin_add_i == 1)
192
+ if (use_builtin_add_i < 0)
193
+ git_config_get_bool("add.interactive.usebuiltin",
194
+ &use_builtin_add_i);
195
+
196
+ if (use_builtin_add_i == 1) {
197
+ if (!patch_mode)
198
return !!run_add_i(the_repository, pathspec);
199
+ if (strcmp(patch_mode, "--patch"))
200
+ die("'%s' not yet supported in the built-in add -p",
201
+ patch_mode);
202
+ return !!run_add_p(the_repository, pathspec);
203
}
204
205
argv_array_push(&argv, "add--interactive");