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) 18s,strategy= merge strategy to use 19X= option for selected merge strategy 20m,message= message to be used for the merge commit (if any) 21" 22 23SUBDIRECTORY_OK=Yes 24. git-sh-setup 25require_work_tree 26cd_to_toplevel 27 28test -z"$(git ls-files -u)"|| 29 die "Merge is not possible because you have unmerged files." 30 31!test -e"$GIT_DIR/MERGE_HEAD"|| 32 die 'You have not concluded your merge (MERGE_HEAD exists).' 33 34LF=' 35' 36 37all_strategies='recur recursive octopus resolve stupid ours subtree' 38all_strategies="$all_strategiesrecursive-ours recursive-theirs" 39default_twohead_strategies='recursive' 40default_octopus_strategies='octopus' 41no_fast_forward_strategies='subtree ours' 42no_trivial_strategies='recursive recur subtree ours recursive-ours recursive-theirs' 43use_strategies= 44xopt= 45 46allow_fast_forward=t 47allow_trivial_merge=t 48squash= no_commit= log_arg= 49 50dropsave() { 51rm-f --"$GIT_DIR/MERGE_HEAD""$GIT_DIR/MERGE_MSG" \ 52"$GIT_DIR/MERGE_STASH"||exit1 53} 54 55savestate() { 56# Stash away any local modifications. 57 git stash create >"$GIT_DIR/MERGE_STASH" 58} 59 60restorestate() { 61iftest -f"$GIT_DIR/MERGE_STASH" 62then 63 git reset--hard$head>/dev/null 64 git stash apply $(cat "$GIT_DIR/MERGE_STASH") 65 git update-index --refresh>/dev/null 66fi 67} 68 69finish_up_to_date () { 70case"$squash"in 71 t) 72echo"$1(nothing to squash)";; 73'') 74echo"$1";; 75esac 76 dropsave 77} 78 79squash_message () { 80echo Squashed commit of the following: 81echo 82 git log --no-merges --pretty=medium ^"$head"$remoteheads 83} 84 85finish () { 86iftest''="$2" 87then 88 rlogm="$GIT_REFLOG_ACTION" 89else 90echo"$2" 91 rlogm="$GIT_REFLOG_ACTION:$2" 92fi 93case"$squash"in 94 t) 95echo"Squash commit -- not updating HEAD" 96 squash_message >"$GIT_DIR/SQUASH_MSG" 97;; 98'') 99case"$merge_msg"in 100'') 101echo"No merge message -- not updating HEAD" 102;; 103*) 104 git update-ref -m"$rlogm" HEAD "$1""$head"||exit1 105 git gc --auto 106;; 107esac 108;; 109esac 110case"$1"in 111'') 112;; 113 ?*) 114iftest"$show_diffstat"= t 115then 116# We want color (if set), but no pager 117 GIT_PAGER='' git diff--stat --summary -M"$head""$1" 118fi 119;; 120esac 121 122# Run a post-merge hook 123iftest -x"$GIT_DIR"/hooks/post-merge 124then 125case"$squash"in 126 t) 127"$GIT_DIR"/hooks/post-merge1 128;; 129'') 130"$GIT_DIR"/hooks/post-merge0 131;; 132esac 133fi 134} 135 136merge_name () { 137 remote="$1" 138 rh=$(git rev-parse --verify "$remote^0" 2>/dev/null)||return 139if truname=$(expr "$remote" : '\(.*\)~[0-9]*$') && 140 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null 141 then 142 echo "$rhbranch '$truname' (early part) of ." 143 return 144 fi 145 if found_ref=$(git rev-parse --symbolic-full-name --verify \ 146 "$remote" 2>/dev/null) 147 then 148 if test "${found_ref#refs/heads/}" != "$found_ref" 149 then 150 echo "$rhbranch '$remote' of ." 151 return 152 elif test "${found_ref#refs/remotes/}" != "$found_ref" 153 then 154 echo "$rhremote branch '$remote' of ." 155 return 156 fi 157 fi 158 if test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" 159 then 160 sed -e 's/ not-for-merge/ /' -e 1q \ 161 "$GIT_DIR/FETCH_HEAD" 162 return 163 fi 164 echo "$rhcommit '$remote'" 165} 166 167parse_config () { 168 while test$#!= 0; do 169 case "$1" in 170 -n|--no-stat|--no-summary) 171 show_diffstat=false ;; 172 --stat|--summary) 173 show_diffstat=t ;; 174 --log|--no-log) 175 log_arg=$1;; 176 --squash) 177 test "$allow_fast_forward" = t || 178 die "You cannot combine --squash with --no-ff." 179 squash=t no_commit=t ;; 180 --no-squash) 181 squash= no_commit= ;; 182 --commit) 183 no_commit= ;; 184 --no-commit) 185 no_commit=t ;; 186 --ff) 187 allow_fast_forward=t ;; 188 --no-ff) 189 test "$squash" != t || 190 die "You cannot combine --squash with --no-ff." 191 allow_fast_forward=f ;; 192 -s|--strategy) 193 shift 194 case "$all_strategies" in 195 *"$1"*) 196 use_strategies="$use_strategies$1" 197 ;; 198 *) 199 type "git-merge-$1" >/dev/null 2>&1 || 200 die "available strategies are:$all_strategies" 201 use_strategies="$use_strategies$1" 202 ;; 203 esac 204 ;; 205 -X) 206 shift 207 xopt="${xopt:+$xopt }$(git rev-parse --sq-quote "--$1")" 208 ;; 209 -m|--message) 210 shift 211 merge_msg="$1" 212 have_message=t 213 ;; 214 --) 215 shift 216 break ;; 217 *) usage ;; 218 esac 219 shift 220 done 221 args_left=$# 222} 223 224test$#!= 0 || usage 225 226have_message= 227 228if branch=$(git-symbolic-ref -q HEAD) 229then 230 mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") 231 if test -n "$mergeopts" 232 then 233 parse_config$mergeopts-- 234 fi 235fi 236 237parse_config "$@" 238while test$args_left-lt$#; do shift; done 239 240if test -z "$show_diffstat"; then 241 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 242 test "$(git config --bool merge.stat)" = false && show_diffstat=false 243 test -z "$show_diffstat" && show_diffstat=t 244fi 245 246# This could be traditional "merge <msg> HEAD <commit>..." and the 247# way we can tell it is to see if the second token is HEAD, but some 248# people might have misused the interface and used a committish that 249# is the same as HEAD there instead. Traditional format never would 250# have "-m" so it is an additional safety measure to check for it. 251 252if test -z "$have_message" && 253 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 254 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 255 test "$second_token" = "$head_commit" 256then 257 merge_msg="$1" 258 shift 259 head_arg="$1" 260 shift 261elif ! git rev-parse --verify HEAD >/dev/null 2>&1 262then 263 # If the merged head is a valid one there is no reason to 264 # forbid "git merge" into a branch yet to be born. We do 265 # the same for "git pull". 266 if test 1 -ne$# 267 then 268 echo >&2 "Can merge only exactly one commit into empty head" 269 exit 1 270 fi 271 272 test "$squash" != t || 273 die "Squash commit into empty head not supported yet" 274 test "$allow_fast_forward" = t || 275 die "Non-fast-forward into an empty head does not make sense" 276 rh=$(git rev-parse --verify "$1^0")|| 277 die "$1- not something we can merge" 278 279 git update-ref -m "initial pull" HEAD "$rh" "" && 280 git read-tree --reset -u HEAD 281 exit 282 283else 284 # We are invoked directly as the first-class UI. 285 head_arg=HEAD 286 287 # All the rest are the commits being merged; prepare 288 # the standard merge summary message to be appended to 289 # the given message. If remote is invalid we will die 290 # later in the common codepath so we discard the error 291 # in this loop. 292 merge_name=$(for remote 293 do 294 merge_name "$remote" 295 done | git fmt-merge-msg$log_arg 296 ) 297 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" 298fi 299head=$(git rev-parse --verify "$head_arg"^0)|| usage 300 301# All the rest are remote heads 302test "$#" = 0 && usage ;# we need at least one remote head. 303set_reflog_action "merge $*" 304 305remoteheads= 306for remote 307do 308 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 309 die "$remote- not something we can merge" 310 remoteheads="${remoteheads}$remotehead" 311 eval GITHEAD_$remotehead='"$remote"' 312 export GITHEAD_$remotehead 313done 314set x$remoteheads; shift 315 316case "$use_strategies" in 317'') 318 case "$#" in 319 1) 320 var="`git config --get pull.twohead`" 321 if test -n "$var" 322 then 323 use_strategies="$var" 324 else 325 use_strategies="$default_twohead_strategies" 326 fi ;; 327 *) 328 var="`git config --get pull.octopus`" 329 if test -n "$var" 330 then 331 use_strategies="$var" 332 else 333 use_strategies="$default_octopus_strategies" 334 fi ;; 335 esac 336 ;; 337esac 338 339for s in$use_strategies 340do 341 for ss in$no_fast_forward_strategies 342 do 343 case "$s" in 344 *"$ss"*) 345 allow_fast_forward=f 346 break 347 ;; 348 esac 349 done 350 for ss in$no_trivial_strategies 351 do 352 case "$s" in 353 *"$ss"*) 354 allow_trivial_merge=f 355 break 356 ;; 357 esac 358 done 359done 360 361case "$#" in 3621) 363 common=$(git merge-base --all $head "$@") 364 ;; 365*) 366 common=$(git show-branch --merge-base $head "$@") 367 ;; 368esac 369echo "$head" >"$GIT_DIR/ORIG_HEAD" 370 371case "$allow_fast_forward,$#,$common,$no_commit" in 372?,*,'',*) 373 # No common ancestors found. We need a real merge. 374 ;; 375?,1,"$1",*) 376 # If head can reach all the merge then we are up to date. 377 # but first the most common case of merging one remote. 378 finish_up_to_date "Already up-to-date." 379 exit 0 380 ;; 381t,1,"$head",*) 382 # Again the most common case of merging one remote. 383 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 384 git update-index --refresh 2>/dev/null 385 msg="Fast-forward" 386 if test -n "$have_message" 387 then 388 msg="$msg(no commit created; -m option ignored)" 389 fi 390 new_head=$(git rev-parse --verify "$1^0")&& 391 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 392 finish "$new_head" "$msg" || exit 393 dropsave 394 exit 0 395 ;; 396?,1,?*"$LF"?*,*) 397 # We are not doing octopus and not fast-forward. Need a 398 # real merge. 399 ;; 400?,1,*,) 401 # We are not doing octopus, not fast-forward, and have only 402 # one common. 403 git update-index --refresh 2>/dev/null 404 case "$allow_trivial_merge" in 405 t) 406 # See if it is really trivial. 407 git var GIT_COMMITTER_IDENT >/dev/null || exit 408 echo "Trying really trivial in-index merge..." 409 if git read-tree --trivial -m -u -v$common$head"$1" && 410 result_tree=$(git write-tree) 411 then 412 echo "Wonderful." 413 result_commit=$( 414 printf '%s\n' "$merge_msg" | 415 git commit-tree$result_tree-p HEAD -p "$1" 416 ) || exit 417 finish "$result_commit" "In-index merge" 418 dropsave 419 exit 0 420 fi 421 echo "Nope." 422 esac 423 ;; 424*) 425 # An octopus. If we can reach all the remote we are up to date. 426 up_to_date=t 427 for remote 428 do 429 common_one=$(git merge-base --all $head $remote) 430 if test "$common_one" != "$remote" 431 then 432 up_to_date=f 433 break 434 fi 435 done 436 if test "$up_to_date" = t 437 then 438 finish_up_to_date "Already up-to-date. Yeeah!" 439 exit 0 440 fi 441 ;; 442esac 443 444# We are going to make a new commit. 445git var GIT_COMMITTER_IDENT >/dev/null || exit 446 447# At this point, we need a real merge. No matter what strategy 448# we use, it would operate on the index, possibly affecting the 449# working tree, and when resolved cleanly, have the desired tree 450# in the index -- this means that the index must be in sync with 451# the$headcommit. The strategies are responsible to ensure this. 452 453case "$use_strategies" in 454?*''?*) 455 # Stash away the local changes so that we can try more than one. 456 savestate 457 single_strategy=no 458 ;; 459*) 460 rm -f "$GIT_DIR/MERGE_STASH" 461 single_strategy=yes 462 ;; 463esac 464 465result_tree= best_cnt=-1 best_strategy= wt_strategy= 466merge_was_ok= 467for strategy in$use_strategies 468do 469 test "$wt_strategy" = '' || { 470 echo "Rewinding the tree to pristine..." 471 restorestate 472 } 473 case "$single_strategy" in 474 no) 475 echo "Trying merge strategy$strategy..." 476 ;; 477 esac 478 479 # Remember which strategy left the state in the working tree 480 wt_strategy=$strategy 481 482 eval 'git-merge-$strategy'"$xopt"'$common--"$head_arg""$@"' 483 exit=$? 484 if test "$no_commit" = t && test "$exit" = 0 485 then 486 merge_was_ok=t 487 exit=1 ;# pretend it left conflicts. 488 fi 489 490 test "$exit" = 0 || { 491 492 # The backend exits with 1 when conflicts are left to be resolved, 493 # with 2 when it does not handle the given merge at all. 494 495 if test "$exit" -eq 1 496 then 497 cnt=`{ 498 git diff-files --name-only 499 git ls-files --unmerged 500 } | wc -l` 501 if test$best_cnt-le 0 -o$cnt-le$best_cnt 502 then 503 best_strategy=$strategy 504 best_cnt=$cnt 505 fi 506 fi 507 continue 508 } 509 510 # Automerge succeeded. 511 result_tree=$(git write-tree)&& break 512done 513 514# If we have a resulting tree, that means the strategy module 515# auto resolved the merge cleanly. 516if test '' != "$result_tree" 517then 518 if test "$allow_fast_forward" = "t" 519 then 520 parents=$(git show-branch --independent "$head" "$@") 521 else 522 parents=$(git rev-parse "$head" "$@") 523 fi 524 parents=$(echo "$parents" | sed -e 's/^/-p /') 525 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 526 finish "$result_commit" "Merge made by$wt_strategy." 527 dropsave 528 exit 0 529fi 530 531# Pick the result from the best strategy and have the user fix it up. 532case "$best_strategy" in 533'') 534 restorestate 535 case "$use_strategies" in 536 ?*''?*) 537 echo >&2 "No merge strategy handled the merge." 538 ;; 539 *) 540 echo >&2 "Merge with strategy$use_strategiesfailed." 541 ;; 542 esac 543 exit 2 544 ;; 545"$wt_strategy") 546 # We already have its result in the working tree. 547 ;; 548*) 549 echo "Rewinding the tree to pristine..." 550 restorestate 551 echo "Using the$best_strategyto prepare resolving by hand." 552 git-merge-$best_strategy$common-- "$head_arg" "$@" 553 ;; 554esac 555 556if test "$squash" = t 557then 558 finish 559else 560 for remote 561 do 562 echo$remote 563 done >"$GIT_DIR/MERGE_HEAD" 564 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" 565fi 566 567if test "$merge_was_ok" = t 568then 569 echo >&2 \ 570 "Automatic merge went well; stopped before committing as requested" 571 exit 0 572else 573 { 574 echo ' 575Conflicts: 576' 577 git ls-files --unmerged | 578 sed -e 's/^[^ ]* / /' | 579 uniq 580 } >>"$GIT_DIR/MERGE_MSG" 581 git rerere 582 die "Automatic merge failed; fix conflicts and then commit the result." 583fi