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$1" ;; 197 *) 198 die "available strategies are:$all_strategies" ;; 199 esac 200 ;; 201 -X) 202 shift 203 xopt="${xopt:+$xopt }$(git rev-parse --sq-quote "--$1")" 204 ;; 205 -m|--message) 206 shift 207 merge_msg="$1" 208 have_message=t 209 ;; 210 --) 211 shift 212 break ;; 213 *) usage ;; 214 esac 215 shift 216 done 217 args_left=$# 218} 219 220test$#!= 0 || usage 221 222have_message= 223 224if branch=$(git-symbolic-ref -q HEAD) 225then 226 mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") 227 if test -n "$mergeopts" 228 then 229 parse_config$mergeopts-- 230 fi 231fi 232 233parse_config "$@" 234while test$args_left-lt$#; do shift; done 235 236if test -z "$show_diffstat"; then 237 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 238 test "$(git config --bool merge.stat)" = false && show_diffstat=false 239 test -z "$show_diffstat" && show_diffstat=t 240fi 241 242# This could be traditional "merge <msg> HEAD <commit>..." and the 243# way we can tell it is to see if the second token is HEAD, but some 244# people might have misused the interface and used a committish that 245# is the same as HEAD there instead. Traditional format never would 246# have "-m" so it is an additional safety measure to check for it. 247 248if test -z "$have_message" && 249 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 250 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 251 test "$second_token" = "$head_commit" 252then 253 merge_msg="$1" 254 shift 255 head_arg="$1" 256 shift 257elif ! git rev-parse --verify HEAD >/dev/null 2>&1 258then 259 # If the merged head is a valid one there is no reason to 260 # forbid "git merge" into a branch yet to be born. We do 261 # the same for "git pull". 262 if test 1 -ne$# 263 then 264 echo >&2 "Can merge only exactly one commit into empty head" 265 exit 1 266 fi 267 268 test "$squash" != t || 269 die "Squash commit into empty head not supported yet" 270 test "$allow_fast_forward" = t || 271 die "Non-fast-forward into an empty head does not make sense" 272 rh=$(git rev-parse --verify "$1^0")|| 273 die "$1- not something we can merge" 274 275 git update-ref -m "initial pull" HEAD "$rh" "" && 276 git read-tree --reset -u HEAD 277 exit 278 279else 280 # We are invoked directly as the first-class UI. 281 head_arg=HEAD 282 283 # All the rest are the commits being merged; prepare 284 # the standard merge summary message to be appended to 285 # the given message. If remote is invalid we will die 286 # later in the common codepath so we discard the error 287 # in this loop. 288 merge_name=$(for remote 289 do 290 merge_name "$remote" 291 done | git fmt-merge-msg$log_arg 292 ) 293 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" 294fi 295head=$(git rev-parse --verify "$head_arg"^0)|| usage 296 297# All the rest are remote heads 298test "$#" = 0 && usage ;# we need at least one remote head. 299set_reflog_action "merge $*" 300 301remoteheads= 302for remote 303do 304 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 305 die "$remote- not something we can merge" 306 remoteheads="${remoteheads}$remotehead" 307 eval GITHEAD_$remotehead='"$remote"' 308 export GITHEAD_$remotehead 309done 310set x$remoteheads; shift 311 312case "$use_strategies" in 313'') 314 case "$#" in 315 1) 316 var="`git config --get pull.twohead`" 317 if test -n "$var" 318 then 319 use_strategies="$var" 320 else 321 use_strategies="$default_twohead_strategies" 322 fi ;; 323 *) 324 var="`git config --get pull.octopus`" 325 if test -n "$var" 326 then 327 use_strategies="$var" 328 else 329 use_strategies="$default_octopus_strategies" 330 fi ;; 331 esac 332 ;; 333esac 334 335for s in$use_strategies 336do 337 for ss in$no_fast_forward_strategies 338 do 339 case "$s" in 340 *"$ss"*) 341 allow_fast_forward=f 342 break 343 ;; 344 esac 345 done 346 for ss in$no_trivial_strategies 347 do 348 case "$s" in 349 *"$ss"*) 350 allow_trivial_merge=f 351 break 352 ;; 353 esac 354 done 355done 356 357case "$#" in 3581) 359 common=$(git merge-base --all $head "$@") 360 ;; 361*) 362 common=$(git show-branch --merge-base $head "$@") 363 ;; 364esac 365echo "$head" >"$GIT_DIR/ORIG_HEAD" 366 367case "$allow_fast_forward,$#,$common,$no_commit" in 368?,*,'',*) 369 # No common ancestors found. We need a real merge. 370 ;; 371?,1,"$1",*) 372 # If head can reach all the merge then we are up to date. 373 # but first the most common case of merging one remote. 374 finish_up_to_date "Already up-to-date." 375 exit 0 376 ;; 377t,1,"$head",*) 378 # Again the most common case of merging one remote. 379 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 380 git update-index --refresh 2>/dev/null 381 msg="Fast-forward" 382 if test -n "$have_message" 383 then 384 msg="$msg(no commit created; -m option ignored)" 385 fi 386 new_head=$(git rev-parse --verify "$1^0")&& 387 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 388 finish "$new_head" "$msg" || exit 389 dropsave 390 exit 0 391 ;; 392?,1,?*"$LF"?*,*) 393 # We are not doing octopus and not fast-forward. Need a 394 # real merge. 395 ;; 396?,1,*,) 397 # We are not doing octopus, not fast-forward, and have only 398 # one common. 399 git update-index --refresh 2>/dev/null 400 case "$allow_trivial_merge" in 401 t) 402 # See if it is really trivial. 403 git var GIT_COMMITTER_IDENT >/dev/null || exit 404 echo "Trying really trivial in-index merge..." 405 if git read-tree --trivial -m -u -v$common$head"$1" && 406 result_tree=$(git write-tree) 407 then 408 echo "Wonderful." 409 result_commit=$( 410 printf '%s\n' "$merge_msg" | 411 git commit-tree$result_tree-p HEAD -p "$1" 412 ) || exit 413 finish "$result_commit" "In-index merge" 414 dropsave 415 exit 0 416 fi 417 echo "Nope." 418 esac 419 ;; 420*) 421 # An octopus. If we can reach all the remote we are up to date. 422 up_to_date=t 423 for remote 424 do 425 common_one=$(git merge-base --all $head $remote) 426 if test "$common_one" != "$remote" 427 then 428 up_to_date=f 429 break 430 fi 431 done 432 if test "$up_to_date" = t 433 then 434 finish_up_to_date "Already up-to-date. Yeeah!" 435 exit 0 436 fi 437 ;; 438esac 439 440# We are going to make a new commit. 441git var GIT_COMMITTER_IDENT >/dev/null || exit 442 443# At this point, we need a real merge. No matter what strategy 444# we use, it would operate on the index, possibly affecting the 445# working tree, and when resolved cleanly, have the desired tree 446# in the index -- this means that the index must be in sync with 447# the$headcommit. The strategies are responsible to ensure this. 448 449case "$use_strategies" in 450?*''?*) 451 # Stash away the local changes so that we can try more than one. 452 savestate 453 single_strategy=no 454 ;; 455*) 456 rm -f "$GIT_DIR/MERGE_STASH" 457 single_strategy=yes 458 ;; 459esac 460 461result_tree= best_cnt=-1 best_strategy= wt_strategy= 462merge_was_ok= 463for strategy in$use_strategies 464do 465 test "$wt_strategy" = '' || { 466 echo "Rewinding the tree to pristine..." 467 restorestate 468 } 469 case "$single_strategy" in 470 no) 471 echo "Trying merge strategy$strategy..." 472 ;; 473 esac 474 475 # Remember which strategy left the state in the working tree 476 wt_strategy=$strategy 477 478 eval 'git-merge-$strategy'"$xopt"'$common--"$head_arg""$@"' 479 exit=$? 480 if test "$no_commit" = t && test "$exit" = 0 481 then 482 merge_was_ok=t 483 exit=1 ;# pretend it left conflicts. 484 fi 485 486 test "$exit" = 0 || { 487 488 # The backend exits with 1 when conflicts are left to be resolved, 489 # with 2 when it does not handle the given merge at all. 490 491 if test "$exit" -eq 1 492 then 493 cnt=`{ 494 git diff-files --name-only 495 git ls-files --unmerged 496 } | wc -l` 497 if test$best_cnt-le 0 -o$cnt-le$best_cnt 498 then 499 best_strategy=$strategy 500 best_cnt=$cnt 501 fi 502 fi 503 continue 504 } 505 506 # Automerge succeeded. 507 result_tree=$(git write-tree)&& break 508done 509 510# If we have a resulting tree, that means the strategy module 511# auto resolved the merge cleanly. 512if test '' != "$result_tree" 513then 514 if test "$allow_fast_forward" = "t" 515 then 516 parents=$(git show-branch --independent "$head" "$@") 517 else 518 parents=$(git rev-parse "$head" "$@") 519 fi 520 parents=$(echo "$parents" | sed -e 's/^/-p /') 521 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 522 finish "$result_commit" "Merge made by$wt_strategy." 523 dropsave 524 exit 0 525fi 526 527# Pick the result from the best strategy and have the user fix it up. 528case "$best_strategy" in 529'') 530 restorestate 531 case "$use_strategies" in 532 ?*''?*) 533 echo >&2 "No merge strategy handled the merge." 534 ;; 535 *) 536 echo >&2 "Merge with strategy$use_strategiesfailed." 537 ;; 538 esac 539 exit 2 540 ;; 541"$wt_strategy") 542 # We already have its result in the working tree. 543 ;; 544*) 545 echo "Rewinding the tree to pristine..." 546 restorestate 547 echo "Using the$best_strategyto prepare resolving by hand." 548 git-merge-$best_strategy$common-- "$head_arg" "$@" 549 ;; 550esac 551 552if test "$squash" = t 553then 554 finish 555else 556 for remote 557 do 558 echo$remote 559 done >"$GIT_DIR/MERGE_HEAD" 560 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" 561fi 562 563if test "$merge_was_ok" = t 564then 565 echo >&2 \ 566 "Automatic merge went well; stopped before committing as requested" 567 exit 0 568else 569 { 570 echo ' 571Conflicts: 572' 573 git ls-files --unmerged | 574 sed -e 's/^[^ ]* / /' | 575 uniq 576 } >>"$GIT_DIR/MERGE_MSG" 577 git rerere 578 die "Automatic merge failed; fix conflicts and then commit the result." 579fi