apply: register conflicted stages to the index

Now we have all the necessary logic to fall back on three-way merge when
the patch does not cleanly apply, insert the conflicted entries to the
index as appropriate.  This obviously triggers only when the "--index"
option is used.

When we fall back to three-way merge and some of the merges fail, just
like the case where the "--reject" option was specified and we had to
write some "*.rej" files out for unapplicable patches, exit the command
with non-zero status without showing the diffstat and summary.  Otherwise
they would make the list of problematic paths scroll off the display.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/apply.c b/builtin/apply.c
index 24efb3f438ef16a9a42a869dcebfcfa66a6669cd..dc52c9475e5f250912b01c80a261185d0b9034b9 100644 (file)
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -3288,7 +3288,10 @@ static int try_threeway(struct image *image, struct patch *patch,
 
        if (status) {
                patch->conflicted_threeway = 1;
-               hashcpy(patch->threeway_stage[0], pre_sha1);
+               if (patch->is_new)
+                       hashclr(patch->threeway_stage[0]);
+               else
+                       hashcpy(patch->threeway_stage[0], pre_sha1);
                hashcpy(patch->threeway_stage[1], our_sha1);
                hashcpy(patch->threeway_stage[2], post_sha1);
                fprintf(stderr, "Applied patch to '%s' with conflicts.\n", patch->new_name);
@@ -3852,6 +3855,32 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
        die_errno(_("unable to write file '%s' mode %o"), path, mode);
 }
 
+static void add_conflicted_stages_file(struct patch *patch)
+{
+       int stage, namelen;
+       unsigned ce_size, mode;
+       struct cache_entry *ce;
+
+       if (!update_index)
+               return;
+       namelen = strlen(patch->new_name);
+       ce_size = cache_entry_size(namelen);
+       mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
+
+       remove_file_from_cache(patch->new_name);
+       for (stage = 1; stage < 4; stage++) {
+               if (is_null_sha1(patch->threeway_stage[stage - 1]))
+                       continue;
+               ce = xcalloc(1, ce_size);
+               memcpy(ce->name, patch->new_name, namelen);
+               ce->ce_mode = create_ce_mode(mode);
+               ce->ce_flags = create_ce_flags(namelen, stage);
+               hashcpy(ce->sha1, patch->threeway_stage[stage - 1]);
+               if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
+                       die(_("unable to add cache entry for %s"), patch->new_name);
+       }
+}
+
 static void create_file(struct patch *patch)
 {
        char *path = patch->new_name;
@@ -3862,7 +3891,11 @@ static void create_file(struct patch *patch)
        if (!mode)
                mode = S_IFREG | 0644;
        create_one_file(path, mode, buf, size);
-       add_index_file(path, mode, buf, size);
+
+       if (patch->conflicted_threeway)
+               add_conflicted_stages_file(patch);
+       else
+               add_index_file(path, mode, buf, size);
 }
 
 /* phase zero is to remove, phase one is to create */
@@ -3964,6 +3997,7 @@ static int write_out_results(struct patch *list)
        int phase;
        int errs = 0;
        struct patch *l;
+       struct string_list cpath = STRING_LIST_INIT_DUP;
 
        for (phase = 0; phase < 2; phase++) {
                l = list;
@@ -3972,12 +4006,28 @@ static int write_out_results(struct patch *list)
                                errs = 1;
                        else {
                                write_out_one_result(l, phase);
-                               if (phase == 1 && write_out_one_reject(l))
-                                       errs = 1;
+                               if (phase == 1) {
+                                       if (write_out_one_reject(l))
+                                               errs = 1;
+                                       if (l->conflicted_threeway) {
+                                               string_list_append(&cpath, l->new_name);
+                                               errs = 1;
+                                       }
+                               }
                        }
                        l = l->next;
                }
        }
+
+       if (cpath.nr) {
+               struct string_list_item *item;
+
+               sort_string_list(&cpath);
+               for_each_string_list_item(item, &cpath)
+                       fprintf(stderr, "U %s\n", item->string);
+               string_list_clear(&cpath, 0);
+       }
+
        return errs;
 }
 
@@ -4100,8 +4150,12 @@ static int apply_patch(int fd, const char *filename, int options)
            !apply_with_reject)
                exit(1);
 
-       if (apply && write_out_results(list))
-               exit(1);
+       if (apply && write_out_results(list)) {
+               if (apply_with_reject)
+                       exit(1);
+               /* with --3way, we still need to write the index out */
+               return 1;
+       }
 
        if (fake_ancestor)
                build_fake_ancestor(list, fake_ancestor);

diff --git a/t/t4108-apply-threeway.sh b/t/t4108-apply-threeway.sh
new file mode 100755 (executable)
index 0000000..475dfb5
--- /dev/null
+++ b/t/t4108-apply-threeway.sh
@@ -0,0 +1,78 @@
+#!/bin/sh
+
+test_description='git apply --3way'
+
+. ./test-lib.sh
+
+create_file () {
+       for i
+       do
+               echo "$i"
+       done
+}
+
+sanitize_conflicted_diff () {
+       sed -e '
+               /^index /d
+               s/^\(+[<>][<>][<>][<>]*\) .*/\1/
+       '
+}
+
+test_expect_success setup '
+       test_tick &&
+       create_file >one 1 2 3 4 5 6 7 &&
+       cat one >two &&
+       git add one two &&
+       git commit -m initial &&
+
+       git branch side &&
+
+       test_tick &&
+       create_file >one 1 two 3 4 5 six 7 &&
+       create_file >two 1 two 3 4 5 6 7 &&
+       git commit -a -m master &&
+
+       git checkout side &&
+       create_file >one 1 2 3 4 five 6 7 &&
+       create_file >two 1 2 3 4 five 6 7 &&
+       git commit -a -m side &&
+
+       git checkout master
+'
+
+test_expect_success 'apply without --3way' '
+       git diff side^ side >P.diff &&
+
+       # should fail to apply
+       git reset --hard &&
+       git checkout master^0 &&
+       test_must_fail git apply --index P.diff &&
+       # should leave things intact
+       git diff-files --exit-code &&
+       git diff-index --exit-code --cached HEAD
+'
+
+test_expect_success 'apply with --3way' '
+       # Merging side should be similar to applying this patch
+       git diff ...side >P.diff &&
+
+       # The corresponding conflicted merge
+       git reset --hard &&
+       git checkout master^0 &&
+       test_must_fail git merge --no-commit side &&
+       git ls-files -s >expect.ls &&
+       git diff HEAD | sanitize_conflicted_diff >expect.diff &&
+
+       # should fail to apply
+       git reset --hard &&
+       git checkout master^0 &&
+       test_must_fail git apply --index --3way P.diff &&
+       git ls-files -s >actual.ls &&
+       git diff HEAD | sanitize_conflicted_diff >actual.diff &&
+
+       # The result should resemble the corresponding merge
+       test_cmp expect.ls actual.ls &&
+       test_cmp expect.diff actual.diff
+'
+
+test_done