1#!/bin/sh 2# 3# Copyright (c) 2005 Junio C Hamano 4# 5 6OPTIONS_KEEPDASHDASH= 7OPTIONS_SPEC="\ 8git merge [options] <remote>... 9git merge [options] <msg> HEAD <remote> 10-- 11stat show a diffstat at the end of the merge 12n don't show a diffstat at the end of the merge 13summary (synonym to --stat) 14log add list of one-line log to merge commit message 15squash create a single commit instead of doing a merge 16commit perform a commit if the merge succeeds (default) 17ff allow fast-forward (default) 18ff-only abort if fast-forward is not possible 19s,strategy= merge strategy to use 20X= option for selected merge strategy 21m,message= message to be used for the merge commit (if any) 22" 23 24SUBDIRECTORY_OK=Yes 25. git-sh-setup 26require_work_tree 27cd_to_toplevel 28 29test -z"$(git ls-files -u)"|| 30 die "Merge is not possible because you have unmerged files." 31 32!test -e"$GIT_DIR/MERGE_HEAD"|| 33 die 'You have not concluded your merge (MERGE_HEAD exists).' 34 35LF=' 36' 37 38all_strategies='recur recursive octopus resolve stupid ours subtree' 39all_strategies="$all_strategiesrecursive-ours recursive-theirs" 40not_strategies='base file index tree' 41default_twohead_strategies='recursive' 42default_octopus_strategies='octopus' 43no_fast_forward_strategies='subtree ours' 44no_trivial_strategies='recursive recur subtree ours recursive-ours recursive-theirs' 45use_strategies= 46xopt= 47 48allow_fast_forward=t 49fast_forward_only= 50allow_trivial_merge=t 51squash= no_commit= log_arg= 52 53dropsave() { 54rm-f --"$GIT_DIR/MERGE_HEAD""$GIT_DIR/MERGE_MSG" \ 55"$GIT_DIR/MERGE_STASH""$GIT_DIR/MERGE_MODE"||exit1 56} 57 58savestate() { 59# Stash away any local modifications. 60 git stash create >"$GIT_DIR/MERGE_STASH" 61} 62 63restorestate() { 64iftest -f"$GIT_DIR/MERGE_STASH" 65then 66 git reset--hard$head>/dev/null 67 git stash apply $(cat "$GIT_DIR/MERGE_STASH") 68 git update-index --refresh>/dev/null 69fi 70} 71 72finish_up_to_date () { 73case"$squash"in 74 t) 75echo"$1(nothing to squash)";; 76'') 77echo"$1";; 78esac 79 dropsave 80} 81 82squash_message () { 83echo Squashed commit of the following: 84echo 85 git log --no-merges --pretty=medium ^"$head"$remoteheads 86} 87 88finish () { 89iftest''="$2" 90then 91 rlogm="$GIT_REFLOG_ACTION" 92else 93echo"$2" 94 rlogm="$GIT_REFLOG_ACTION:$2" 95fi 96case"$squash"in 97 t) 98echo"Squash commit -- not updating HEAD" 99 squash_message >"$GIT_DIR/SQUASH_MSG" 100;; 101'') 102case"$merge_msg"in 103'') 104echo"No merge message -- not updating HEAD" 105;; 106*) 107 git update-ref -m"$rlogm" HEAD "$1""$head"||exit1 108 git gc --auto 109;; 110esac 111;; 112esac 113case"$1"in 114'') 115;; 116 ?*) 117iftest"$show_diffstat"= t 118then 119# We want color (if set), but no pager 120 GIT_PAGER='' git diff--stat --summary -M"$head""$1" 121fi 122;; 123esac 124 125# Run a post-merge hook 126iftest -x"$GIT_DIR"/hooks/post-merge 127then 128case"$squash"in 129 t) 130"$GIT_DIR"/hooks/post-merge1 131;; 132'') 133"$GIT_DIR"/hooks/post-merge0 134;; 135esac 136fi 137} 138 139merge_name () { 140 remote="$1" 141 rh=$(git rev-parse --verify "$remote^0" 2>/dev/null)||return 142if truname=$(expr "$remote" : '\(.*\)~[0-9]*$') && 143 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null 144 then 145 echo "$rhbranch '$truname' (early part) of ." 146 return 147 fi 148 if found_ref=$(git rev-parse --symbolic-full-name --verify \ 149 "$remote" 2>/dev/null) 150 then 151 expanded=$(git check-ref-format --branch "$remote")|| 152 exit 153 if test "${found_ref#refs/heads/}" != "$found_ref" 154 then 155 echo "$rhbranch '$expanded' of ." 156 return 157 elif test "${found_ref#refs/remotes/}" != "$found_ref" 158 then 159 echo "$rhremote branch '$expanded' of ." 160 return 161 fi 162 fi 163 if test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" 164 then 165 sed -e 's/ not-for-merge/ /' -e 1q \ 166 "$GIT_DIR/FETCH_HEAD" 167 return 168 fi 169 echo "$rhcommit '$remote'" 170} 171 172parse_config () { 173 while test$#!= 0; do 174 case "$1" in 175 -n|--no-stat|--no-summary) 176 show_diffstat=false ;; 177 --stat|--summary) 178 show_diffstat=t ;; 179 --log|--no-log) 180 log_arg=$1;; 181 --squash) 182 test "$allow_fast_forward" = t || 183 die "You cannot combine --squash with --no-ff." 184 squash=t no_commit=t ;; 185 --no-squash) 186 squash= no_commit= ;; 187 --commit) 188 no_commit= ;; 189 --no-commit) 190 no_commit=t ;; 191 --ff) 192 allow_fast_forward=t ;; 193 --no-ff) 194 test "$squash" != t || 195 die "You cannot combine --squash with --no-ff." 196 test "$fast_forward_only" != t || 197 die "You cannot combine --ff-only with --no-ff." 198 allow_fast_forward=f ;; 199 --ff-only) 200 test "$allow_fast_forward" != f || 201 die "You cannot combine --ff-only with --no-ff." 202 fast_forward_only=t ;; 203 -s|--strategy) 204 shift 205 case "$all_strategies" in 206 *"$1"*) 207 use_strategies="$use_strategies$1" 208 ;; 209 *) 210 case "$not_strategies" in 211 *"$1"*) 212 false 213 esac && 214 type "git-merge-$1" >/dev/null 2>&1 || 215 die "available strategies are:$all_strategies" 216 use_strategies="$use_strategies$1" 217 ;; 218 esac 219 ;; 220 -X) 221 shift 222 xopt="${xopt:+$xopt }$(git rev-parse --sq-quote "--$1")" 223 ;; 224 -m|--message) 225 shift 226 merge_msg="$1" 227 have_message=t 228 ;; 229 --) 230 shift 231 break ;; 232 *) usage ;; 233 esac 234 shift 235 done 236 args_left=$# 237} 238 239test$#!= 0 || usage 240 241have_message= 242 243if branch=$(git-symbolic-ref -q HEAD) 244then 245 mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") 246 if test -n "$mergeopts" 247 then 248 parse_config$mergeopts-- 249 fi 250fi 251 252parse_config "$@" 253while test$args_left-lt$#; do shift; done 254 255if test -z "$show_diffstat"; then 256 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 257 test "$(git config --bool merge.stat)" = false && show_diffstat=false 258 test -z "$show_diffstat" && show_diffstat=t 259fi 260 261# This could be traditional "merge <msg> HEAD <commit>..." and the 262# way we can tell it is to see if the second token is HEAD, but some 263# people might have misused the interface and used a committish that 264# is the same as HEAD there instead. Traditional format never would 265# have "-m" so it is an additional safety measure to check for it. 266 267if test -z "$have_message" && 268 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 269 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 270 test "$second_token" = "$head_commit" 271then 272 merge_msg="$1" 273 shift 274 head_arg="$1" 275 shift 276elif ! git rev-parse --verify HEAD >/dev/null 2>&1 277then 278 # If the merged head is a valid one there is no reason to 279 # forbid "git merge" into a branch yet to be born. We do 280 # the same for "git pull". 281 if test 1 -ne$# 282 then 283 echo >&2 "Can merge only exactly one commit into empty head" 284 exit 1 285 fi 286 287 test "$squash" != t || 288 die "Squash commit into empty head not supported yet" 289 test "$allow_fast_forward" = t || 290 die "Non-fast-forward into an empty head does not make sense" 291 rh=$(git rev-parse --verify "$1^0")|| 292 die "$1- not something we can merge" 293 294 git update-ref -m "initial pull" HEAD "$rh" "" && 295 git read-tree --reset -u HEAD 296 exit 297 298else 299 # We are invoked directly as the first-class UI. 300 head_arg=HEAD 301 302 # All the rest are the commits being merged; prepare 303 # the standard merge summary message to be appended to 304 # the given message. If remote is invalid we will die 305 # later in the common codepath so we discard the error 306 # in this loop. 307 merge_msg="$( 308 for remote 309 do 310 merge_name "$remote" 311 done | 312 if test "$have_message" = t 313 then 314 git fmt-merge-msg -m "$merge_msg"$log_arg 315 else 316 git fmt-merge-msg$log_arg 317 fi 318 )" 319fi 320head=$(git rev-parse --verify "$head_arg"^0)|| usage 321 322# All the rest are remote heads 323test "$#" = 0 && usage ;# we need at least one remote head. 324set_reflog_action "merge $*" 325 326remoteheads= 327for remote 328do 329 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 330 die "$remote- not something we can merge" 331 remoteheads="${remoteheads}$remotehead" 332 eval GITHEAD_$remotehead='"$remote"' 333 export GITHEAD_$remotehead 334done 335set x$remoteheads; shift 336 337case "$use_strategies" in 338'') 339 case "$#" in 340 1) 341 var="`git config --get pull.twohead`" 342 if test -n "$var" 343 then 344 use_strategies="$var" 345 else 346 use_strategies="$default_twohead_strategies" 347 fi ;; 348 *) 349 var="`git config --get pull.octopus`" 350 if test -n "$var" 351 then 352 use_strategies="$var" 353 else 354 use_strategies="$default_octopus_strategies" 355 fi ;; 356 esac 357 ;; 358esac 359 360for s in$use_strategies 361do 362 for ss in$no_fast_forward_strategies 363 do 364 case "$s" in 365 *"$ss"*) 366 allow_fast_forward=f 367 break 368 ;; 369 esac 370 done 371 for ss in$no_trivial_strategies 372 do 373 case "$s" in 374 *"$ss"*) 375 allow_trivial_merge=f 376 break 377 ;; 378 esac 379 done 380done 381 382case "$#" in 3831) 384 common=$(git merge-base --all $head "$@") 385 ;; 386*) 387 common=$(git merge-base --all --octopus $head "$@") 388 ;; 389esac 390echo "$head" >"$GIT_DIR/ORIG_HEAD" 391 392case "$allow_fast_forward,$#,$common,$no_commit" in 393?,*,'',*) 394 # No common ancestors found. We need a real merge. 395 ;; 396?,1,"$1",*) 397 # If head can reach all the merge then we are up to date. 398 # but first the most common case of merging one remote. 399 finish_up_to_date "Already up-to-date." 400 exit 0 401 ;; 402t,1,"$head",*) 403 # Again the most common case of merging one remote. 404 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 405 git update-index --refresh 2>/dev/null 406 msg="Fast-forward" 407 if test -n "$have_message" 408 then 409 msg="$msg(no commit created; -m option ignored)" 410 fi 411 new_head=$(git rev-parse --verify "$1^0")&& 412 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 413 finish "$new_head" "$msg" || exit 414 dropsave 415 exit 0 416 ;; 417?,1,?*"$LF"?*,*) 418 # We are not doing octopus and not fast-forward. Need a 419 # real merge. 420 ;; 421?,1,*,) 422 # We are not doing octopus, not fast-forward, and have only 423 # one common. 424 git update-index --refresh 2>/dev/null 425 case "$allow_trivial_merge,$fast_forward_only" in 426 t,) 427 # See if it is really trivial. 428 git var GIT_COMMITTER_IDENT >/dev/null || exit 429 echo "Trying really trivial in-index merge..." 430 if git read-tree --trivial -m -u -v$common$head"$1" && 431 result_tree=$(git write-tree) 432 then 433 echo "Wonderful." 434 result_commit=$( 435 printf '%s\n' "$merge_msg" | 436 git commit-tree$result_tree-p HEAD -p "$1" 437 ) || exit 438 finish "$result_commit" "In-index merge" 439 dropsave 440 exit 0 441 fi 442 echo "Nope." 443 esac 444 ;; 445*) 446 # An octopus. If we can reach all the remote we are up to date. 447 up_to_date=t 448 for remote 449 do 450 common_one=$(git merge-base --all $head $remote) 451 if test "$common_one" != "$remote" 452 then 453 up_to_date=f 454 break 455 fi 456 done 457 if test "$up_to_date" = t 458 then 459 finish_up_to_date "Already up-to-date. Yeeah!" 460 exit 0 461 fi 462 ;; 463esac 464 465if test "$fast_forward_only" = t 466then 467 die "Not possible to fast-forward, aborting." 468fi 469 470# We are going to make a new commit. 471git var GIT_COMMITTER_IDENT >/dev/null || exit 472 473# At this point, we need a real merge. No matter what strategy 474# we use, it would operate on the index, possibly affecting the 475# working tree, and when resolved cleanly, have the desired tree 476# in the index -- this means that the index must be in sync with 477# the$headcommit. The strategies are responsible to ensure this. 478 479case "$use_strategies" in 480?*''?*) 481 # Stash away the local changes so that we can try more than one. 482 savestate 483 single_strategy=no 484 ;; 485*) 486 rm -f "$GIT_DIR/MERGE_STASH" 487 single_strategy=yes 488 ;; 489esac 490 491result_tree= best_cnt=-1 best_strategy= wt_strategy= 492merge_was_ok= 493for strategy in$use_strategies 494do 495 test "$wt_strategy" = '' || { 496 echo "Rewinding the tree to pristine..." 497 restorestate 498 } 499 case "$single_strategy" in 500 no) 501 echo "Trying merge strategy$strategy..." 502 ;; 503 esac 504 505 # Remember which strategy left the state in the working tree 506 wt_strategy=$strategy 507 508 eval 'git-merge-$strategy'"$xopt"'$common--"$head_arg""$@"' 509 exit=$? 510 if test "$no_commit" = t && test "$exit" = 0 511 then 512 merge_was_ok=t 513 exit=1 ;# pretend it left conflicts. 514 fi 515 516 test "$exit" = 0 || { 517 518 # The backend exits with 1 when conflicts are left to be resolved, 519 # with 2 when it does not handle the given merge at all. 520 521 if test "$exit" -eq 1 522 then 523 cnt=`{ 524 git diff-files --name-only 525 git ls-files --unmerged 526 } | wc -l` 527 if test$best_cnt-le 0 -o$cnt-le$best_cnt 528 then 529 best_strategy=$strategy 530 best_cnt=$cnt 531 fi 532 fi 533 continue 534 } 535 536 # Automerge succeeded. 537 result_tree=$(git write-tree)&& break 538done 539 540# If we have a resulting tree, that means the strategy module 541# auto resolved the merge cleanly. 542if test '' != "$result_tree" 543then 544 if test "$allow_fast_forward" = "t" 545 then 546 parents=$(git merge-base --independent "$head" "$@") 547 else 548 parents=$(git rev-parse "$head" "$@") 549 fi 550 parents=$(echo "$parents" | sed -e 's/^/-p /') 551 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 552 finish "$result_commit" "Merge made by$wt_strategy." 553 dropsave 554 exit 0 555fi 556 557# Pick the result from the best strategy and have the user fix it up. 558case "$best_strategy" in 559'') 560 restorestate 561 case "$use_strategies" in 562 ?*''?*) 563 echo >&2 "No merge strategy handled the merge." 564 ;; 565 *) 566 echo >&2 "Merge with strategy$use_strategiesfailed." 567 ;; 568 esac 569 exit 2 570 ;; 571"$wt_strategy") 572 # We already have its result in the working tree. 573 ;; 574*) 575 echo "Rewinding the tree to pristine..." 576 restorestate 577 echo "Using the$best_strategyto prepare resolving by hand." 578 git-merge-$best_strategy$common-- "$head_arg" "$@" 579 ;; 580esac 581 582if test "$squash" = t 583then 584 finish 585else 586 for remote 587 do 588 echo$remote 589 done >"$GIT_DIR/MERGE_HEAD" 590 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" || 591 die "Could not write to$GIT_DIR/MERGE_MSG" 592 if test "$allow_fast_forward" != t 593 then 594 printf "%s" no-ff 595 else 596 : 597 fi >"$GIT_DIR/MERGE_MODE" || 598 die "Could not write to$GIT_DIR/MERGE_MODE" 599fi 600 601if test "$merge_was_ok" = t 602then 603 echo >&2 \ 604 "Automatic merge went well; stopped before committing as requested" 605 exit 0 606else 607 { 608 echo ' 609Conflicts: 610' 611 git ls-files --unmerged | 612 sed -e 's/^[^ ]* / /' | 613 uniq 614 } >>"$GIT_DIR/MERGE_MSG" 615 git rerere 616 die "Automatic merge failed; fix conflicts and then commit the result." 617fi