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[PATCH] read-tree --emu23.
This new flag causes two-way fast forward to internally use the three-way merge mechanism. This behaviour is intended to offer a better fast forward semantics when used in a dirty work tree. The new test t1005 is parallel to the existing t1001 "pure 2-way" tests, but some parts that are commented out would fail. These failures are due to three-way merge enforcing too strict index requirements for cases that could succeed. This problem will be addressed by later patches. Without even changing three-way mechanism, the --emu23 two-way fast forward already gives the user an easier-to-handle merge result when a file that "merged head" updates has local modifications. This is demonstrated as "case 16" test in t1005. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Junio C Hamano
Linus Torvalds
parent
76bc82ca0e
commit
03efa6d9a4
81
read-tree.c
81
read-tree.c
@ -209,6 +209,58 @@ static int twoway_merge(struct cache_entry **src, struct cache_entry **dst)
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return deleted_entry(oldtree, current, dst);
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}
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/*
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* Two-way merge emulated with three-way merge.
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*
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* This treats "read-tree -m H M" by transforming it internally
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* into "read-tree -m H I+H M", where I+H is a tree that would
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* contain the contents of the current index file, overlayed on
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* top of H. Unlike the traditional two-way merge, this leaves
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* the stages in the resulting index file and lets the user resolve
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* the merge conflicts using standard tools for three-way merge.
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*
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* This function is just to set-up such an arrangement, and the
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* actual merge uses threeway_merge() function.
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*/
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static void setup_emu23(void)
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{
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/* stage0 contains I, stage1 H, stage2 M.
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* move stage2 to stage3, and create stage2 entries
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* by scanning stage0 and stage1 entries.
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*/
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int i, namelen, size;
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struct cache_entry *ce, *stage2;
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for (i = 0; i < active_nr; i++) {
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ce = active_cache[i];
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if (ce_stage(ce) != 2)
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continue;
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/* hoist them up to stage 3 */
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namelen = ce_namelen(ce);
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ce->ce_flags = create_ce_flags(namelen, 3);
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}
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for (i = 0; i < active_nr; i++) {
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ce = active_cache[i];
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if (ce_stage(ce) > 1)
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continue;
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namelen = ce_namelen(ce);
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size = cache_entry_size(namelen);
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stage2 = xmalloc(size);
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memcpy(stage2, ce, size);
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stage2->ce_flags = create_ce_flags(namelen, 2);
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if (add_cache_entry(stage2, ADD_CACHE_OK_TO_ADD) < 0)
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die("cannot merge index and our head tree");
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/* We are done with this name, so skip to next name */
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while (i < active_nr &&
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ce_namelen(active_cache[i]) == namelen &&
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!memcmp(active_cache[i]->name, ce->name, namelen))
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i++;
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i--; /* compensate for the loop control */
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}
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}
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/*
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* One-way merge.
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*
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@ -315,7 +367,7 @@ static struct cache_file cache_file;
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int main(int argc, char **argv)
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{
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int i, newfd, merge, reset;
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int i, newfd, merge, reset, emu23;
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unsigned char sha1[20];
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newfd = hold_index_file_for_update(&cache_file, get_index_file());
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@ -324,6 +376,7 @@ int main(int argc, char **argv)
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merge = 0;
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reset = 0;
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emu23 = 0;
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for (i = 1; i < argc; i++) {
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const char *arg = argv[i];
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@ -335,7 +388,7 @@ int main(int argc, char **argv)
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/* This differs from "-m" in that we'll silently ignore unmerged entries */
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if (!strcmp(arg, "--reset")) {
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if (stage || merge)
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if (stage || merge || emu23)
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usage(read_tree_usage);
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reset = 1;
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merge = 1;
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@ -345,7 +398,7 @@ int main(int argc, char **argv)
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/* "-m" stands for "merge", meaning we start in stage 1 */
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if (!strcmp(arg, "-m")) {
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if (stage || merge)
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if (stage || merge || emu23)
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usage(read_tree_usage);
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if (read_cache_unmerged())
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die("you need to resolve your current index first");
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@ -353,6 +406,17 @@ int main(int argc, char **argv)
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merge = 1;
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continue;
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}
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/* "-emu23" uses 3-way merge logic to perform fast-forward */
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if (!strcmp(arg, "--emu23")) {
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if (stage || merge || emu23)
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usage(read_tree_usage);
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if (read_cache_unmerged())
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die("you need to resolve your current index first");
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merge = emu23 = stage = 1;
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continue;
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}
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if (get_sha1(arg, sha1) < 0)
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usage(read_tree_usage);
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if (stage > 3)
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@ -369,9 +433,18 @@ int main(int argc, char **argv)
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[2] = twoway_merge,
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[3] = threeway_merge,
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};
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merge_fn_t fn;
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if (stage < 2 || stage > 4)
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die("just how do you expect me to merge %d trees?", stage-1);
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merge_cache(active_cache, active_nr, merge_function[stage-1]);
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if (emu23 && stage != 3)
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die("--emu23 takes only two trees");
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fn = merge_function[stage-1];
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if (stage == 3 && emu23) {
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setup_emu23();
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fn = merge_function[3];
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}
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merge_cache(active_cache, active_nr, fn);
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}
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if (write_cache(newfd, active_cache, active_nr) ||
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commit_index_file(&cache_file))
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316
t/t1005-read-tree-m-2way-emu23.sh
Normal file
316
t/t1005-read-tree-m-2way-emu23.sh
Normal file
@ -0,0 +1,316 @@
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#!/bin/sh
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#
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# Copyright (c) 2005 Junio C Hamano
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#
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test_description='Two way merge with read-tree --emu23 $H $M
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This test tries two-way merge (aka fast forward with carry forward).
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There is the head (called H) and another commit (called M), which is
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simply ahead of H. The index and the work tree contains a state that
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is derived from H, but may also have local changes. This test checks
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all the combinations described in the two-tree merge "carry forward"
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rules, found in <Documentation/git-rev-tree.txt>.
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In the test, these paths are used:
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bozbar - in H, stays in M, modified from bozbar to gnusto
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frotz - not in H added in M
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nitfol - in H, stays in M unmodified
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rezrov - in H, deleted in M
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yomin - not in H nor M
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'
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. ./test-lib.sh
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read_tree_twoway () {
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git-read-tree --emu23 "$1" "$2" &&
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git-ls-files --stage &&
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git-merge-cache git-merge-one-file-script -a &&
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git-ls-files --stage
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}
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_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
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_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
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compare_change () {
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cat current
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sed -n >current \
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-e '/^--- /d; /^+++ /d; /^@@ /d;' \
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-e 's/^\([-+][0-7][0-7][0-7][0-7][0-7][0-7]\) '"$_x40"' /\1 X /p' \
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"$1"
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diff -u expected current
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}
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check_cache_at () {
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clean_if_empty=`git-diff-files "$1"`
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case "$clean_if_empty" in
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'') echo "$1: clean" ;;
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?*) echo "$1: dirty" ;;
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esac
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case "$2,$clean_if_empty" in
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clean,) : ;;
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clean,?*) false ;;
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dirty,) false ;;
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dirty,?*) : ;;
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esac
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}
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check_stages () {
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cat >expected_stages
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git-ls-files --stage | sed -e "s/ $_x40 / X /" >current_stages
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diff -u expected_stages current_stages
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}
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test_expect_success \
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setup \
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'echo frotz >frotz &&
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echo nitfol >nitfol &&
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echo bozbar >bozbar &&
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echo rezrov >rezrov &&
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echo yomin >yomin &&
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git-update-cache --add nitfol bozbar rezrov &&
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treeH=`git-write-tree` &&
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echo treeH $treeH &&
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git-ls-tree $treeH &&
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echo gnusto >bozbar &&
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git-update-cache --add frotz bozbar --force-remove rezrov &&
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git-ls-files --stage >M.out &&
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treeM=`git-write-tree` &&
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echo treeM $treeM &&
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git-ls-tree $treeM &&
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git-diff-tree $treeH $treeM'
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test_expect_success \
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'1, 2, 3 - no carry forward' \
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'rm -f .git/index &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >1-3.out &&
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diff -u M.out 1-3.out &&
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check_cache_at bozbar dirty &&
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check_cache_at frotz clean && # different from pure 2-way
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check_cache_at nitfol dirty'
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echo '+100644 X 0 yomin' >expected
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test_expect_success \
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'4 - carry forward local addition.' \
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'rm -f .git/index &&
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git-update-cache --add yomin &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >4.out || exit
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diff -u M.out 4.out >4diff.out
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compare_change 4diff.out expected &&
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check_cache_at yomin clean'
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# "read-tree -m H I+H M" where !H && !M; so (I+H) not being up-to-date
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# should not matter, but without #3ALT this does not work.
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: test_expect_success \
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'5 - carry forward local addition.' \
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'rm -f .git/index &&
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echo yomin >yomin &&
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git-update-cache --add yomin &&
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echo yomin yomin >yomin &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >5.out || exit
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diff -u M.out 5.out >5diff.out
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compare_change 5diff.out expected &&
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check_cache_at yomin dirty'
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# "read-tree -m H I+H M" where !H && M && (I+H) == M, so this should
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# succeed (even the entry is clean), but without #5ALT this does not
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# work.
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: test_expect_success \
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'6 - local addition already has the same.' \
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'rm -f .git/index &&
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git-update-cache --add frotz &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >6.out &&
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diff -u M.out 6.out &&
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check_cache_at frotz clean'
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# Exactly the same pattern as above but with dirty cache. This also
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# should succeed, but without #5ALT it does not.
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: test_expect_success \
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'7 - local addition already has the same.' \
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'rm -f .git/index &&
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echo frotz >frotz &&
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git-update-cache --add frotz &&
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echo frotz frotz >frotz &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >7.out &&
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diff -u M.out 7.out &&
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check_cache_at frotz dirty'
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test_expect_success \
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'8 - conflicting addition.' \
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'rm -f .git/index &&
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echo frotz frotz >frotz &&
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git-update-cache --add frotz &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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test_expect_success \
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'9 - conflicting addition.' \
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'rm -f .git/index &&
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echo frotz frotz >frotz &&
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git-update-cache --add frotz &&
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echo frotz >frotz &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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test_expect_success \
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'10 - path removed.' \
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'rm -f .git/index &&
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echo rezrov >rezrov &&
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git-update-cache --add rezrov &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >10.out &&
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diff -u M.out 10.out'
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test_expect_success \
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'11 - dirty path removed.' \
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'rm -f .git/index &&
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echo rezrov >rezrov &&
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git-update-cache --add rezrov &&
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echo rezrov rezrov >rezrov &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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test_expect_success \
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'12 - unmatching local changes being removed.' \
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'rm -f .git/index &&
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echo rezrov rezrov >rezrov &&
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git-update-cache --add rezrov &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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test_expect_success \
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'13 - unmatching local changes being removed.' \
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'rm -f .git/index &&
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echo rezrov rezrov >rezrov &&
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git-update-cache --add rezrov &&
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echo rezrov >rezrov &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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cat >expected <<EOF
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-100644 X 0 nitfol
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+100644 X 0 nitfol
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EOF
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test_expect_success \
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'14 - unchanged in two heads.' \
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'rm -f .git/index &&
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echo nitfol nitfol >nitfol &&
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git-update-cache --add nitfol &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >14.out || exit
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diff -u M.out 14.out >14diff.out
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compare_change 14diff.out expected &&
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check_cache_at nitfol clean'
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test_expect_success \
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'15 - unchanged in two heads.' \
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'rm -f .git/index &&
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echo nitfol nitfol >nitfol &&
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git-update-cache --add nitfol &&
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echo nitfol nitfol nitfol >nitfol &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >15.out || exit
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diff -u M.out 15.out >15diff.out
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compare_change 15diff.out expected &&
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check_cache_at nitfol dirty'
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# This is different from straight 2-way merge in that it leaves
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# three stages of bozbar in the index file without failing, so
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# the user can run git-diff-stages to examine the situation.
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test_expect_success \
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'16 - conflicting local change.' \
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'rm -f .git/index &&
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echo bozbar bozbar >bozbar &&
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git-update-cache --add bozbar &&
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git-read-tree --emu23 $treeH $treeM &&
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check_stages' <<\EOF
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100644 X 1 bozbar
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100644 X 2 bozbar
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100644 X 3 bozbar
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100644 X 3 frotz
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100644 X 0 nitfol
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100644 X 1 rezrov
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100644 X 2 rezrov
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EOF
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test_expect_success \
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'17 - conflicting local change.' \
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'rm -f .git/index &&
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echo bozbar bozbar >bozbar &&
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git-update-cache --add bozbar &&
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echo bozbar bozbar bozbar >bozbar &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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test_expect_success \
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'18 - local change already having a good result.' \
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'rm -f .git/index &&
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echo gnusto >bozbar &&
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git-update-cache --add bozbar &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >18.out &&
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diff -u M.out 18.out &&
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check_cache_at bozbar clean'
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test_expect_success \
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'19 - local change already having a good result, further modified.' \
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'rm -f .git/index &&
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echo gnusto >bozbar &&
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git-update-cache --add bozbar &&
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echo gnusto gnusto >bozbar &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >19.out &&
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diff -u M.out 19.out &&
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check_cache_at bozbar dirty'
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test_expect_success \
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'20 - no local change, use new tree.' \
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'rm -f .git/index &&
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echo bozbar >bozbar &&
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git-update-cache --add bozbar &&
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read_tree_twoway $treeH $treeM &&
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git-ls-files --stage >20.out &&
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diff -u M.out 20.out &&
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check_cache_at bozbar dirty'
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test_expect_success \
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'21 - no local change, dirty cache.' \
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'rm -f .git/index &&
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echo bozbar >bozbar &&
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git-update-cache --add bozbar &&
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echo gnusto gnusto >bozbar &&
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if read_tree_twoway $treeH $treeM; then false; else :; fi'
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# Also make sure we did not break DF vs DF/DF case.
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test_expect_success \
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'DF vs DF/DF case setup.' \
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'rm -f .git/index &&
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echo DF >DF &&
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git-update-cache --add DF &&
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treeDF=`git-write-tree` &&
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echo treeDF $treeDF &&
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git-ls-tree $treeDF &&
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rm -f DF &&
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mkdir DF &&
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echo DF/DF >DF/DF &&
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git-update-cache --add --remove DF DF/DF &&
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treeDFDF=`git-write-tree` &&
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echo treeDFDF $treeDFDF &&
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git-ls-tree $treeDFDF &&
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git-ls-files --stage >DFDF.out'
|
||||
|
||||
test_expect_success \
|
||||
'DF vs DF/DF case test.' \
|
||||
'rm -f .git/index &&
|
||||
rm -fr DF &&
|
||||
echo DF >DF &&
|
||||
git-update-cache --add DF &&
|
||||
read_tree_twoway $treeDF $treeDFDF &&
|
||||
git-ls-files --stage >DFDFcheck.out &&
|
||||
diff -u DFDF.out DFDFcheck.out &&
|
||||
check_cache_at DF/DF clean && # different from pure 2-way
|
||||
:'
|
||||
|
||||
test_done
|
||||
Loading…
Reference in New Issue
Block a user