1#!/bin/sh 2# 3# Copyright (c) 2005 Junio C Hamano 4# 5 6USAGE='[-n] [--summary] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+' 7 8SUBDIRECTORY_OK=Yes 9. git-sh-setup 10require_work_tree 11cd_to_toplevel 12 13test -z"$(git ls-files -u)"|| 14 die "You are in the middle of a conflicted merge." 15 16LF=' 17' 18 19all_strategies='recur recursive octopus resolve stupid ours subtree' 20default_twohead_strategies='recursive' 21default_octopus_strategies='octopus' 22no_fast_forward_strategies='subtree ours' 23no_trivial_strategies='recursive recur subtree ours' 24use_strategies= 25 26allow_fast_forward=t 27allow_trivial_merge=t 28 29dropsave() { 30rm-f --"$GIT_DIR/MERGE_HEAD""$GIT_DIR/MERGE_MSG" \ 31"$GIT_DIR/MERGE_SAVE"||exit1 32} 33 34savestate() { 35# Stash away any local modifications. 36 git diff-index -z --name-only$head| 37cpio-0 -o>"$GIT_DIR/MERGE_SAVE" 38} 39 40restorestate() { 41iftest -f"$GIT_DIR/MERGE_SAVE" 42then 43 git reset--hard$head>/dev/null 44cpio-iuv<"$GIT_DIR/MERGE_SAVE" 45 git update-index --refresh>/dev/null 46fi 47} 48 49finish_up_to_date () { 50case"$squash"in 51 t) 52echo"$1(nothing to squash)";; 53'') 54echo"$1";; 55esac 56 dropsave 57} 58 59squash_message () { 60echo Squashed commit of the following: 61echo 62 git log --no-merges ^"$head"$remoteheads 63} 64 65finish () { 66iftest''="$2" 67then 68 rlogm="$GIT_REFLOG_ACTION" 69else 70echo"$2" 71 rlogm="$GIT_REFLOG_ACTION:$2" 72fi 73case"$squash"in 74 t) 75echo"Squash commit -- not updating HEAD" 76 squash_message >"$GIT_DIR/SQUASH_MSG" 77;; 78'') 79case"$merge_msg"in 80'') 81echo"No merge message -- not updating HEAD" 82;; 83*) 84 git update-ref -m"$rlogm" HEAD "$1""$head"||exit1 85;; 86esac 87;; 88esac 89case"$1"in 90'') 91;; 92 ?*) 93iftest"$show_diffstat"= t 94then 95# We want color (if set), but no pager 96 GIT_PAGER='' git diff--stat --summary -M"$head""$1" 97fi 98;; 99esac 100} 101 102merge_name () { 103 remote="$1" 104 rh=$(git rev-parse --verify "$remote^0" 2>/dev/null)||return 105 bh=$(git show-ref -s --verify "refs/heads/$remote" 2>/dev/null) 106iftest"$rh"="$bh" 107then 108echo"$rhbranch '$remote' of ." 109elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') && 110 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null 111 then 112 echo "$rhbranch '$truname' (early part) of ." 113 elif test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" 114 then 115 sed -e 's/ not-for-merge/ /' -e 1q \ 116 "$GIT_DIR/FETCH_HEAD" 117 else 118 echo "$rhcommit '$remote'" 119 fi 120} 121 122parse_option () { 123 case "$1" in 124 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\ 125 --no-summa|--no-summar|--no-summary) 126 show_diffstat=false ;; 127 --summary) 128 show_diffstat=t ;; 129 --sq|--squ|--squa|--squas|--squash) 130 squash=t no_commit=t ;; 131 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit) 132 no_commit=t ;; 133 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\ 134 --strateg=*|--strategy=*|\ 135 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy) 136 case "$#,$1" in 137 *,*=*) 138 strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;; 139 1,*) 140 usage ;; 141 *) 142 strategy="$2" 143 shift ;; 144 esac 145 case "$all_strategies" in 146 *"$strategy"*) 147 use_strategies="$use_strategies$strategy" ;; 148 *) 149 die "available strategies are:$all_strategies" ;; 150 esac 151 ;; 152 -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*) 153 merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'` 154 have_message=t 155 ;; 156 -m|--m|--me|--mes|--mess|--messa|--messag|--message) 157 shift 158 case "$#" in 159 1) usage ;; 160 esac 161 merge_msg="$1" 162 have_message=t 163 ;; 164 -*) usage ;; 165 *) return 1 ;; 166 esac 167 shift 168 args_left=$# 169} 170 171parse_config () { 172 while test$#-gt 0 173 do 174 parse_option "$@" || usage 175 while test$args_left-lt$# 176 do 177 shift 178 done 179 done 180} 181 182test$#!= 0 || usage 183 184have_message= 185 186if branch=$(git-symbolic-ref -q HEAD) 187then 188 mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions") 189 if test -n "$mergeopts" 190 then 191 parse_config$mergeopts 192 fi 193fi 194 195while parse_option "$@" 196do 197 while test$args_left-lt$# 198 do 199 shift 200 done 201done 202 203if test -z "$show_diffstat"; then 204 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 205 test -z "$show_diffstat" && show_diffstat=t 206fi 207 208# This could be traditional "merge <msg> HEAD <commit>..." and the 209# way we can tell it is to see if the second token is HEAD, but some 210# people might have misused the interface and used a committish that 211# is the same as HEAD there instead. Traditional format never would 212# have "-m" so it is an additional safety measure to check for it. 213 214if test -z "$have_message" && 215 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 216 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 217 test "$second_token" = "$head_commit" 218then 219 merge_msg="$1" 220 shift 221 head_arg="$1" 222 shift 223elif ! git rev-parse --verify HEAD >/dev/null 2>&1 224then 225 # If the merged head is a valid one there is no reason to 226 # forbid "git merge" into a branch yet to be born. We do 227 # the same for "git pull". 228 if test 1 -ne$# 229 then 230 echo >&2 "Can merge only exactly one commit into empty head" 231 exit 1 232 fi 233 234 rh=$(git rev-parse --verify "$1^0")|| 235 die "$1- not something we can merge" 236 237 git update-ref -m "initial pull" HEAD "$rh" "" && 238 git read-tree --reset -u HEAD 239 exit 240 241else 242 # We are invoked directly as the first-class UI. 243 head_arg=HEAD 244 245 # All the rest are the commits being merged; prepare 246 # the standard merge summary message to be appended to 247 # the given message. If remote is invalid we will die 248 # later in the common codepath so we discard the error 249 # in this loop. 250 merge_name=$(for remote 251 do 252 merge_name "$remote" 253 done | git fmt-merge-msg 254 ) 255 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" 256fi 257head=$(git rev-parse --verify "$head_arg"^0)|| usage 258 259# All the rest are remote heads 260test "$#" = 0 && usage ;# we need at least one remote head. 261set_reflog_action "merge $*" 262 263remoteheads= 264for remote 265do 266 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 267 die "$remote- not something we can merge" 268 remoteheads="${remoteheads}$remotehead" 269 eval GITHEAD_$remotehead='"$remote"' 270 export GITHEAD_$remotehead 271done 272set x$remoteheads; shift 273 274case "$use_strategies" in 275'') 276 case "$#" in 277 1) 278 var="`git config --get pull.twohead`" 279 if test -n "$var" 280 then 281 use_strategies="$var" 282 else 283 use_strategies="$default_twohead_strategies" 284 fi ;; 285 *) 286 var="`git config --get pull.octopus`" 287 if test -n "$var" 288 then 289 use_strategies="$var" 290 else 291 use_strategies="$default_octopus_strategies" 292 fi ;; 293 esac 294 ;; 295esac 296 297for s in$use_strategies 298do 299 for ss in$no_fast_forward_strategies 300 do 301 case "$s" in 302 *"$ss"*) 303 allow_fast_forward=f 304 break 305 ;; 306 esac 307 done 308 for ss in$no_trivial_strategies 309 do 310 case "$s" in 311 *"$ss"*) 312 allow_trivial_merge=f 313 break 314 ;; 315 esac 316 done 317done 318 319case "$#" in 3201) 321 common=$(git merge-base --all $head "$@") 322 ;; 323*) 324 common=$(git show-branch --merge-base $head "$@") 325 ;; 326esac 327echo "$head" >"$GIT_DIR/ORIG_HEAD" 328 329case "$allow_fast_forward,$#,$common,$no_commit" in 330?,*,'',*) 331 # No common ancestors found. We need a real merge. 332 ;; 333?,1,"$1",*) 334 # If head can reach all the merge then we are up to date. 335 # but first the most common case of merging one remote. 336 finish_up_to_date "Already up-to-date." 337 exit 0 338 ;; 339t,1,"$head",*) 340 # Again the most common case of merging one remote. 341 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 342 git update-index --refresh 2>/dev/null 343 msg="Fast forward" 344 if test -n "$have_message" 345 then 346 msg="$msg(no commit created; -m option ignored)" 347 fi 348 new_head=$(git rev-parse --verify "$1^0")&& 349 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 350 finish "$new_head" "$msg" || exit 351 dropsave 352 exit 0 353 ;; 354?,1,?*"$LF"?*,*) 355 # We are not doing octopus and not fast forward. Need a 356 # real merge. 357 ;; 358?,1,*,) 359 # We are not doing octopus, not fast forward, and have only 360 # one common. 361 git update-index --refresh 2>/dev/null 362 case "$allow_trivial_merge" in 363 t) 364 # See if it is really trivial. 365 git var GIT_COMMITTER_IDENT >/dev/null || exit 366 echo "Trying really trivial in-index merge..." 367 if git read-tree --trivial -m -u -v$common$head"$1" && 368 result_tree=$(git write-tree) 369 then 370 echo "Wonderful." 371 result_commit=$( 372 printf '%s\n' "$merge_msg" | 373 git commit-tree$result_tree-p HEAD -p "$1" 374 ) || exit 375 finish "$result_commit" "In-index merge" 376 dropsave 377 exit 0 378 fi 379 echo "Nope." 380 esac 381 ;; 382*) 383 # An octopus. If we can reach all the remote we are up to date. 384 up_to_date=t 385 for remote 386 do 387 common_one=$(git merge-base --all $head $remote) 388 if test "$common_one" != "$remote" 389 then 390 up_to_date=f 391 break 392 fi 393 done 394 if test "$up_to_date" = t 395 then 396 finish_up_to_date "Already up-to-date. Yeeah!" 397 exit 0 398 fi 399 ;; 400esac 401 402# We are going to make a new commit. 403git var GIT_COMMITTER_IDENT >/dev/null || exit 404 405# At this point, we need a real merge. No matter what strategy 406# we use, it would operate on the index, possibly affecting the 407# working tree, and when resolved cleanly, have the desired tree 408# in the index -- this means that the index must be in sync with 409# the$headcommit. The strategies are responsible to ensure this. 410 411case "$use_strategies" in 412?*''?*) 413 # Stash away the local changes so that we can try more than one. 414 savestate 415 single_strategy=no 416 ;; 417*) 418 rm -f "$GIT_DIR/MERGE_SAVE" 419 single_strategy=yes 420 ;; 421esac 422 423result_tree= best_cnt=-1 best_strategy= wt_strategy= 424merge_was_ok= 425for strategy in$use_strategies 426do 427 test "$wt_strategy" = '' || { 428 echo "Rewinding the tree to pristine..." 429 restorestate 430 } 431 case "$single_strategy" in 432 no) 433 echo "Trying merge strategy$strategy..." 434 ;; 435 esac 436 437 # Remember which strategy left the state in the working tree 438 wt_strategy=$strategy 439 440 git-merge-$strategy$common-- "$head_arg" "$@" 441 exit=$? 442 if test "$no_commit" = t && test "$exit" = 0 443 then 444 merge_was_ok=t 445 exit=1 ;# pretend it left conflicts. 446 fi 447 448 test "$exit" = 0 || { 449 450 # The backend exits with 1 when conflicts are left to be resolved, 451 # with 2 when it does not handle the given merge at all. 452 453 if test "$exit" -eq 1 454 then 455 cnt=`{ 456 git diff-files --name-only 457 git ls-files --unmerged 458 } | wc -l` 459 if test$best_cnt-le 0 -o$cnt-le$best_cnt 460 then 461 best_strategy=$strategy 462 best_cnt=$cnt 463 fi 464 fi 465 continue 466 } 467 468 # Automerge succeeded. 469 result_tree=$(git write-tree)&& break 470done 471 472# If we have a resulting tree, that means the strategy module 473# auto resolved the merge cleanly. 474if test '' != "$result_tree" 475then 476 parents=$(git show-branch --independent "$head" "$@" | sed -e 's/^/-p /') 477 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 478 finish "$result_commit" "Merge made by$wt_strategy." 479 dropsave 480 exit 0 481fi 482 483# Pick the result from the best strategy and have the user fix it up. 484case "$best_strategy" in 485'') 486 restorestate 487 case "$use_strategies" in 488 ?*''?*) 489 echo >&2 "No merge strategy handled the merge." 490 ;; 491 *) 492 echo >&2 "Merge with strategy$use_strategiesfailed." 493 ;; 494 esac 495 exit 2 496 ;; 497"$wt_strategy") 498 # We already have its result in the working tree. 499 ;; 500*) 501 echo "Rewinding the tree to pristine..." 502 restorestate 503 echo "Using the$best_strategyto prepare resolving by hand." 504 git-merge-$best_strategy$common-- "$head_arg" "$@" 505 ;; 506esac 507 508if test "$squash" = t 509then 510 finish 511else 512 for remote 513 do 514 echo$remote 515 done >"$GIT_DIR/MERGE_HEAD" 516 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" 517fi 518 519if test "$merge_was_ok" = t 520then 521 echo >&2 \ 522 "Automatic merge went well; stopped before committing as requested" 523 exit 0 524else 525 { 526 echo ' 527Conflicts: 528' 529 git ls-files --unmerged | 530 sed -e 's/^[^ ]* / /' | 531 uniq 532 } >>"$GIT_DIR/MERGE_MSG" 533 git rerere 534 die "Automatic merge failed; fix conflicts and then commit the result." 535fi