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,no-stat don't show a diffstat at the end of the merge 13summary (synonym to --stat) 14no-summary (synonym to --no-stat) 15squash create a single commit instead of doing a merge 16commit perform a commit if the merge sucesses (default) 17ff allow fast forward (default) 18s,strategy= merge strategy to use 19m,message= message to be used for the merge commit (if any) 20" 21 22SUBDIRECTORY_OK=Yes 23. git-sh-setup 24require_work_tree 25cd_to_toplevel 26 27test -z"$(git ls-files -u)"|| 28 die "You are in the middle of a conflicted merge." 29 30LF=' 31' 32 33all_strategies='recur recursive octopus resolve stupid ours subtree' 34default_twohead_strategies='recursive' 35default_octopus_strategies='octopus' 36no_fast_forward_strategies='subtree ours' 37no_trivial_strategies='recursive recur subtree ours' 38use_strategies= 39 40allow_fast_forward=t 41allow_trivial_merge=t 42squash= no_commit= 43 44dropsave() { 45rm-f --"$GIT_DIR/MERGE_HEAD""$GIT_DIR/MERGE_MSG" \ 46"$GIT_DIR/MERGE_STASH"||exit1 47} 48 49savestate() { 50# Stash away any local modifications. 51 git stash create >"$GIT_DIR/MERGE_STASH" 52} 53 54restorestate() { 55iftest -f"$GIT_DIR/MERGE_STASH" 56then 57 git reset--hard$head>/dev/null 58 git stash apply $(cat "$GIT_DIR/MERGE_STASH") 59 git update-index --refresh>/dev/null 60fi 61} 62 63finish_up_to_date () { 64case"$squash"in 65 t) 66echo"$1(nothing to squash)";; 67'') 68echo"$1";; 69esac 70 dropsave 71} 72 73squash_message () { 74echo Squashed commit of the following: 75echo 76 git log --no-merges --pretty=medium ^"$head"$remoteheads 77} 78 79finish () { 80iftest''="$2" 81then 82 rlogm="$GIT_REFLOG_ACTION" 83else 84echo"$2" 85 rlogm="$GIT_REFLOG_ACTION:$2" 86fi 87case"$squash"in 88 t) 89echo"Squash commit -- not updating HEAD" 90 squash_message >"$GIT_DIR/SQUASH_MSG" 91;; 92'') 93case"$merge_msg"in 94'') 95echo"No merge message -- not updating HEAD" 96;; 97*) 98 git update-ref -m"$rlogm" HEAD "$1""$head"||exit1 99 git gc --auto 100;; 101esac 102;; 103esac 104case"$1"in 105'') 106;; 107 ?*) 108iftest"$show_diffstat"= t 109then 110# We want color (if set), but no pager 111 GIT_PAGER='' git diff--stat --summary -M"$head""$1" 112fi 113;; 114esac 115 116# Run a post-merge hook 117iftest -x"$GIT_DIR"/hooks/post-merge 118then 119case"$squash"in 120 t) 121"$GIT_DIR"/hooks/post-merge1 122;; 123'') 124"$GIT_DIR"/hooks/post-merge0 125;; 126esac 127fi 128} 129 130merge_name () { 131 remote="$1" 132 rh=$(git rev-parse --verify "$remote^0" 2>/dev/null)||return 133 bh=$(git show-ref -s --verify "refs/heads/$remote" 2>/dev/null) 134iftest"$rh"="$bh" 135then 136echo"$rhbranch '$remote' of ." 137elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') && 138 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null 139 then 140 echo "$rhbranch '$truname' (early part) of ." 141 elif test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" 142 then 143 sed -e 's/ not-for-merge/ /' -e 1q \ 144 "$GIT_DIR/FETCH_HEAD" 145 else 146 echo "$rhcommit '$remote'" 147 fi 148} 149 150parse_config () { 151 while test$#!= 0; do 152 case "$1" in 153 -n|--no-stat|--no-summary) 154 show_diffstat=false ;; 155 --stat|--summary) 156 show_diffstat=t ;; 157 --squash) 158 test "$allow_fast_forward" = t || 159 die "You cannot combine --squash with --no-ff." 160 squash=t no_commit=t ;; 161 --no-squash) 162 squash= no_commit= ;; 163 --commit) 164 no_commit= ;; 165 --no-commit) 166 no_commit=t ;; 167 --ff) 168 allow_fast_forward=t ;; 169 --no-ff) 170 test "$squash" != t || 171 die "You cannot combine --squash with --no-ff." 172 allow_fast_forward=f ;; 173 -s|--strategy) 174 shift 175 case "$all_strategies" in 176 *"$1"*) 177 use_strategies="$use_strategies$1" ;; 178 *) 179 die "available strategies are:$all_strategies" ;; 180 esac 181 ;; 182 -m|--message) 183 shift 184 merge_msg="$1" 185 have_message=t 186 ;; 187 --) 188 shift 189 break ;; 190 *) usage ;; 191 esac 192 shift 193 done 194 args_left=$# 195} 196 197test$#!= 0 || usage 198 199have_message= 200 201if branch=$(git-symbolic-ref -q HEAD) 202then 203 mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") 204 if test -n "$mergeopts" 205 then 206 parse_config$mergeopts-- 207 fi 208fi 209 210parse_config "$@" 211while test$args_left-lt$#; do shift; done 212 213if test -z "$show_diffstat"; then 214 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 215 test "$(git config --bool merge.stat)" = false && show_diffstat=false 216 test -z "$show_diffstat" && show_diffstat=t 217fi 218 219# This could be traditional "merge <msg> HEAD <commit>..." and the 220# way we can tell it is to see if the second token is HEAD, but some 221# people might have misused the interface and used a committish that 222# is the same as HEAD there instead. Traditional format never would 223# have "-m" so it is an additional safety measure to check for it. 224 225if test -z "$have_message" && 226 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 227 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 228 test "$second_token" = "$head_commit" 229then 230 merge_msg="$1" 231 shift 232 head_arg="$1" 233 shift 234elif ! git rev-parse --verify HEAD >/dev/null 2>&1 235then 236 # If the merged head is a valid one there is no reason to 237 # forbid "git merge" into a branch yet to be born. We do 238 # the same for "git pull". 239 if test 1 -ne$# 240 then 241 echo >&2 "Can merge only exactly one commit into empty head" 242 exit 1 243 fi 244 245 rh=$(git rev-parse --verify "$1^0")|| 246 die "$1- not something we can merge" 247 248 git update-ref -m "initial pull" HEAD "$rh" "" && 249 git read-tree --reset -u HEAD 250 exit 251 252else 253 # We are invoked directly as the first-class UI. 254 head_arg=HEAD 255 256 # All the rest are the commits being merged; prepare 257 # the standard merge summary message to be appended to 258 # the given message. If remote is invalid we will die 259 # later in the common codepath so we discard the error 260 # in this loop. 261 merge_name=$(for remote 262 do 263 merge_name "$remote" 264 done | git fmt-merge-msg 265 ) 266 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" 267fi 268head=$(git rev-parse --verify "$head_arg"^0)|| usage 269 270# All the rest are remote heads 271test "$#" = 0 && usage ;# we need at least one remote head. 272set_reflog_action "merge $*" 273 274remoteheads= 275for remote 276do 277 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 278 die "$remote- not something we can merge" 279 remoteheads="${remoteheads}$remotehead" 280 eval GITHEAD_$remotehead='"$remote"' 281 export GITHEAD_$remotehead 282done 283set x$remoteheads; shift 284 285case "$use_strategies" in 286'') 287 case "$#" in 288 1) 289 var="`git config --get pull.twohead`" 290 if test -n "$var" 291 then 292 use_strategies="$var" 293 else 294 use_strategies="$default_twohead_strategies" 295 fi ;; 296 *) 297 var="`git config --get pull.octopus`" 298 if test -n "$var" 299 then 300 use_strategies="$var" 301 else 302 use_strategies="$default_octopus_strategies" 303 fi ;; 304 esac 305 ;; 306esac 307 308for s in$use_strategies 309do 310 for ss in$no_fast_forward_strategies 311 do 312 case "$s" in 313 *"$ss"*) 314 allow_fast_forward=f 315 break 316 ;; 317 esac 318 done 319 for ss in$no_trivial_strategies 320 do 321 case "$s" in 322 *"$ss"*) 323 allow_trivial_merge=f 324 break 325 ;; 326 esac 327 done 328done 329 330case "$#" in 3311) 332 common=$(git merge-base --all $head "$@") 333 ;; 334*) 335 common=$(git show-branch --merge-base $head "$@") 336 ;; 337esac 338echo "$head" >"$GIT_DIR/ORIG_HEAD" 339 340case "$allow_fast_forward,$#,$common,$no_commit" in 341?,*,'',*) 342 # No common ancestors found. We need a real merge. 343 ;; 344?,1,"$1",*) 345 # If head can reach all the merge then we are up to date. 346 # but first the most common case of merging one remote. 347 finish_up_to_date "Already up-to-date." 348 exit 0 349 ;; 350t,1,"$head",*) 351 # Again the most common case of merging one remote. 352 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 353 git update-index --refresh 2>/dev/null 354 msg="Fast forward" 355 if test -n "$have_message" 356 then 357 msg="$msg(no commit created; -m option ignored)" 358 fi 359 new_head=$(git rev-parse --verify "$1^0")&& 360 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 361 finish "$new_head" "$msg" || exit 362 dropsave 363 exit 0 364 ;; 365?,1,?*"$LF"?*,*) 366 # We are not doing octopus and not fast forward. Need a 367 # real merge. 368 ;; 369?,1,*,) 370 # We are not doing octopus, not fast forward, and have only 371 # one common. 372 git update-index --refresh 2>/dev/null 373 case "$allow_trivial_merge" in 374 t) 375 # See if it is really trivial. 376 git var GIT_COMMITTER_IDENT >/dev/null || exit 377 echo "Trying really trivial in-index merge..." 378 if git read-tree --trivial -m -u -v$common$head"$1" && 379 result_tree=$(git write-tree) 380 then 381 echo "Wonderful." 382 result_commit=$( 383 printf '%s\n' "$merge_msg" | 384 git commit-tree$result_tree-p HEAD -p "$1" 385 ) || exit 386 finish "$result_commit" "In-index merge" 387 dropsave 388 exit 0 389 fi 390 echo "Nope." 391 esac 392 ;; 393*) 394 # An octopus. If we can reach all the remote we are up to date. 395 up_to_date=t 396 for remote 397 do 398 common_one=$(git merge-base --all $head $remote) 399 if test "$common_one" != "$remote" 400 then 401 up_to_date=f 402 break 403 fi 404 done 405 if test "$up_to_date" = t 406 then 407 finish_up_to_date "Already up-to-date. Yeeah!" 408 exit 0 409 fi 410 ;; 411esac 412 413# We are going to make a new commit. 414git var GIT_COMMITTER_IDENT >/dev/null || exit 415 416# At this point, we need a real merge. No matter what strategy 417# we use, it would operate on the index, possibly affecting the 418# working tree, and when resolved cleanly, have the desired tree 419# in the index -- this means that the index must be in sync with 420# the$headcommit. The strategies are responsible to ensure this. 421 422case "$use_strategies" in 423?*''?*) 424 # Stash away the local changes so that we can try more than one. 425 savestate 426 single_strategy=no 427 ;; 428*) 429 rm -f "$GIT_DIR/MERGE_STASH" 430 single_strategy=yes 431 ;; 432esac 433 434result_tree= best_cnt=-1 best_strategy= wt_strategy= 435merge_was_ok= 436for strategy in$use_strategies 437do 438 test "$wt_strategy" = '' || { 439 echo "Rewinding the tree to pristine..." 440 restorestate 441 } 442 case "$single_strategy" in 443 no) 444 echo "Trying merge strategy$strategy..." 445 ;; 446 esac 447 448 # Remember which strategy left the state in the working tree 449 wt_strategy=$strategy 450 451 git-merge-$strategy$common-- "$head_arg" "$@" 452 exit=$? 453 if test "$no_commit" = t && test "$exit" = 0 454 then 455 merge_was_ok=t 456 exit=1 ;# pretend it left conflicts. 457 fi 458 459 test "$exit" = 0 || { 460 461 # The backend exits with 1 when conflicts are left to be resolved, 462 # with 2 when it does not handle the given merge at all. 463 464 if test "$exit" -eq 1 465 then 466 cnt=`{ 467 git diff-files --name-only 468 git ls-files --unmerged 469 } | wc -l` 470 if test$best_cnt-le 0 -o$cnt-le$best_cnt 471 then 472 best_strategy=$strategy 473 best_cnt=$cnt 474 fi 475 fi 476 continue 477 } 478 479 # Automerge succeeded. 480 result_tree=$(git write-tree)&& break 481done 482 483# If we have a resulting tree, that means the strategy module 484# auto resolved the merge cleanly. 485if test '' != "$result_tree" 486then 487 if test "$allow_fast_forward" = "t" 488 then 489 parents=$(git show-branch --independent "$head" "$@") 490 else 491 parents=$(git rev-parse "$head" "$@") 492 fi 493 parents=$(echo "$parents" | sed -e 's/^/-p /') 494 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 495 finish "$result_commit" "Merge made by$wt_strategy." 496 dropsave 497 exit 0 498fi 499 500# Pick the result from the best strategy and have the user fix it up. 501case "$best_strategy" in 502'') 503 restorestate 504 case "$use_strategies" in 505 ?*''?*) 506 echo >&2 "No merge strategy handled the merge." 507 ;; 508 *) 509 echo >&2 "Merge with strategy$use_strategiesfailed." 510 ;; 511 esac 512 exit 2 513 ;; 514"$wt_strategy") 515 # We already have its result in the working tree. 516 ;; 517*) 518 echo "Rewinding the tree to pristine..." 519 restorestate 520 echo "Using the$best_strategyto prepare resolving by hand." 521 git-merge-$best_strategy$common-- "$head_arg" "$@" 522 ;; 523esac 524 525if test "$squash" = t 526then 527 finish 528else 529 for remote 530 do 531 echo$remote 532 done >"$GIT_DIR/MERGE_HEAD" 533 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" 534fi 535 536if test "$merge_was_ok" = t 537then 538 echo >&2 \ 539 "Automatic merge went well; stopped before committing as requested" 540 exit 0 541else 542 { 543 echo ' 544Conflicts: 545' 546 git ls-files --unmerged | 547 sed -e 's/^[^ ]* / /' | 548 uniq 549 } >>"$GIT_DIR/MERGE_MSG" 550 git rerere 551 die "Automatic merge failed; fix conflicts and then commit the result." 552fi