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"$remote 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""$1" 97fi 98;; 99esac 100 101# Run a post-merge hook 102iftest -x"$GIT_DIR"/hooks/post-merge 103then 104case"$squash"in 105 t) 106"$GIT_DIR"/hooks/post-merge1 107;; 108'') 109"$GIT_DIR"/hooks/post-merge0 110;; 111esac 112fi 113} 114 115merge_name () { 116 remote="$1" 117 rh=$(git rev-parse --verify "$remote^0" 2>/dev/null)||return 118 bh=$(git show-ref -s --verify "refs/heads/$remote" 2>/dev/null) 119iftest"$rh"="$bh" 120then 121echo"$rhbranch '$remote' of ." 122elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') && 123 git show-ref -q --verify "refs/heads/$truname" 2>/dev/null 124 then 125 echo "$rhbranch '$truname' (early part) of ." 126 elif test "$remote" = "FETCH_HEAD" -a -r "$GIT_DIR/FETCH_HEAD" 127 then 128 sed -e 's/ not-for-merge/ /' -e 1q \ 129 "$GIT_DIR/FETCH_HEAD" 130 else 131 echo "$rhcommit '$remote'" 132 fi 133} 134 135case "$#" in 0) usage ;; esac 136 137have_message= 138while test$#!= 0 139do 140 case "$1" in 141 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\ 142 --no-summa|--no-summar|--no-summary) 143 show_diffstat=false ;; 144 --summary) 145 show_diffstat=t ;; 146 --sq|--squ|--squa|--squas|--squash) 147 squash=t no_commit=t ;; 148 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit) 149 no_commit=t ;; 150 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\ 151 --strateg=*|--strategy=*|\ 152 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy) 153 case "$#,$1" in 154 *,*=*) 155 strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;; 156 1,*) 157 usage ;; 158 *) 159 strategy="$2" 160 shift ;; 161 esac 162 case "$all_strategies" in 163 *"$strategy"*) 164 use_strategies="$use_strategies$strategy" ;; 165 *) 166 die "available strategies are:$all_strategies" ;; 167 esac 168 ;; 169 -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*) 170 merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'` 171 have_message=t 172 ;; 173 -m|--m|--me|--mes|--mess|--messa|--messag|--message) 174 shift 175 case "$#" in 176 1) usage ;; 177 esac 178 merge_msg="$1" 179 have_message=t 180 ;; 181 -*) usage ;; 182 *) break ;; 183 esac 184 shift 185done 186 187if test -z "$show_diffstat"; then 188 test "$(git config --bool merge.diffstat)" = false && show_diffstat=false 189 test -z "$show_diffstat" && show_diffstat=t 190fi 191 192# This could be traditional "merge <msg> HEAD <commit>..." and the 193# way we can tell it is to see if the second token is HEAD, but some 194# people might have misused the interface and used a committish that 195# is the same as HEAD there instead. Traditional format never would 196# have "-m" so it is an additional safety measure to check for it. 197 198if test -z "$have_message" && 199 second_token=$(git rev-parse --verify "$2^0" 2>/dev/null)&& 200 head_commit=$(git rev-parse --verify "HEAD" 2>/dev/null)&& 201 test "$second_token" = "$head_commit" 202then 203 merge_msg="$1" 204 shift 205 head_arg="$1" 206 shift 207elif ! git rev-parse --verify HEAD >/dev/null 2>&1 208then 209 # If the merged head is a valid one there is no reason to 210 # forbid "git merge" into a branch yet to be born. We do 211 # the same for "git pull". 212 if test 1 -ne$# 213 then 214 echo >&2 "Can merge only exactly one commit into empty head" 215 exit 1 216 fi 217 218 rh=$(git rev-parse --verify "$1^0")|| 219 die "$1- not something we can merge" 220 221 git update-ref -m "initial pull" HEAD "$rh" "" && 222 git read-tree --reset -u HEAD 223 exit 224 225else 226 # We are invoked directly as the first-class UI. 227 head_arg=HEAD 228 229 # All the rest are the commits being merged; prepare 230 # the standard merge summary message to be appended to 231 # the given message. If remote is invalid we will die 232 # later in the common codepath so we discard the error 233 # in this loop. 234 merge_name=$(for remote 235 do 236 merge_name "$remote" 237 done | git fmt-merge-msg 238 ) 239 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name" 240fi 241head=$(git rev-parse --verify "$head_arg"^0)|| usage 242 243# All the rest are remote heads 244test "$#" = 0 && usage ;# we need at least one remote head. 245set_reflog_action "merge $*" 246 247remoteheads= 248for remote 249do 250 remotehead=$(git rev-parse --verify "$remote"^0 2>/dev/null)|| 251 die "$remote- not something we can merge" 252 remoteheads="${remoteheads}$remotehead" 253 eval GITHEAD_$remotehead='"$remote"' 254 export GITHEAD_$remotehead 255done 256set x$remoteheads; shift 257 258case "$use_strategies" in 259'') 260 case "$#" in 261 1) 262 var="`git config --get pull.twohead`" 263 if test -n "$var" 264 then 265 use_strategies="$var" 266 else 267 use_strategies="$default_twohead_strategies" 268 fi ;; 269 *) 270 var="`git config --get pull.octopus`" 271 if test -n "$var" 272 then 273 use_strategies="$var" 274 else 275 use_strategies="$default_octopus_strategies" 276 fi ;; 277 esac 278 ;; 279esac 280 281for s in$use_strategies 282do 283 for ss in$no_fast_forward_strategies 284 do 285 case "$s" in 286 *"$ss"*) 287 allow_fast_forward=f 288 break 289 ;; 290 esac 291 done 292 for ss in$no_trivial_strategies 293 do 294 case "$s" in 295 *"$ss"*) 296 allow_trivial_merge=f 297 break 298 ;; 299 esac 300 done 301done 302 303case "$#" in 3041) 305 common=$(git merge-base --all $head "$@") 306 ;; 307*) 308 common=$(git show-branch --merge-base $head "$@") 309 ;; 310esac 311echo "$head" >"$GIT_DIR/ORIG_HEAD" 312 313case "$allow_fast_forward,$#,$common,$no_commit" in 314?,*,'',*) 315 # No common ancestors found. We need a real merge. 316 ;; 317?,1,"$1",*) 318 # If head can reach all the merge then we are up to date. 319 # but first the most common case of merging one remote. 320 finish_up_to_date "Already up-to-date." 321 exit 0 322 ;; 323t,1,"$head",*) 324 # Again the most common case of merging one remote. 325 echo "Updating$(git rev-parse --short $head)..$(git rev-parse --short $1)" 326 git update-index --refresh 2>/dev/null 327 msg="Fast forward" 328 if test -n "$have_message" 329 then 330 msg="$msg(no commit created; -m option ignored)" 331 fi 332 new_head=$(git rev-parse --verify "$1^0")&& 333 git read-tree -v -m -u --exclude-per-directory=.gitignore$head"$new_head" && 334 finish "$new_head" "$msg" || exit 335 dropsave 336 exit 0 337 ;; 338?,1,?*"$LF"?*,*) 339 # We are not doing octopus and not fast forward. Need a 340 # real merge. 341 ;; 342?,1,*,) 343 # We are not doing octopus, not fast forward, and have only 344 # one common. 345 git update-index --refresh 2>/dev/null 346 case "$allow_trivial_merge" in 347 t) 348 # See if it is really trivial. 349 git var GIT_COMMITTER_IDENT >/dev/null || exit 350 echo "Trying really trivial in-index merge..." 351 if git read-tree --trivial -m -u -v$common$head"$1" && 352 result_tree=$(git write-tree) 353 then 354 echo "Wonderful." 355 result_commit=$( 356 printf '%s\n' "$merge_msg" | 357 git commit-tree$result_tree-p HEAD -p "$1" 358 ) || exit 359 finish "$result_commit" "In-index merge" 360 dropsave 361 exit 0 362 fi 363 echo "Nope." 364 esac 365 ;; 366*) 367 # An octopus. If we can reach all the remote we are up to date. 368 up_to_date=t 369 for remote 370 do 371 common_one=$(git merge-base --all $head $remote) 372 if test "$common_one" != "$remote" 373 then 374 up_to_date=f 375 break 376 fi 377 done 378 if test "$up_to_date" = t 379 then 380 finish_up_to_date "Already up-to-date. Yeeah!" 381 exit 0 382 fi 383 ;; 384esac 385 386# We are going to make a new commit. 387git var GIT_COMMITTER_IDENT >/dev/null || exit 388 389# At this point, we need a real merge. No matter what strategy 390# we use, it would operate on the index, possibly affecting the 391# working tree, and when resolved cleanly, have the desired tree 392# in the index -- this means that the index must be in sync with 393# the$headcommit. The strategies are responsible to ensure this. 394 395case "$use_strategies" in 396?*''?*) 397 # Stash away the local changes so that we can try more than one. 398 savestate 399 single_strategy=no 400 ;; 401*) 402 rm -f "$GIT_DIR/MERGE_SAVE" 403 single_strategy=yes 404 ;; 405esac 406 407result_tree= best_cnt=-1 best_strategy= wt_strategy= 408merge_was_ok= 409for strategy in$use_strategies 410do 411 test "$wt_strategy" = '' || { 412 echo "Rewinding the tree to pristine..." 413 restorestate 414 } 415 case "$single_strategy" in 416 no) 417 echo "Trying merge strategy$strategy..." 418 ;; 419 esac 420 421 # Remember which strategy left the state in the working tree 422 wt_strategy=$strategy 423 424 git-merge-$strategy$common-- "$head_arg" "$@" 425 exit=$? 426 if test "$no_commit" = t && test "$exit" = 0 427 then 428 merge_was_ok=t 429 exit=1 ;# pretend it left conflicts. 430 fi 431 432 test "$exit" = 0 || { 433 434 # The backend exits with 1 when conflicts are left to be resolved, 435 # with 2 when it does not handle the given merge at all. 436 437 if test "$exit" -eq 1 438 then 439 cnt=`{ 440 git diff-files --name-only 441 git ls-files --unmerged 442 } | wc -l` 443 if test$best_cnt-le 0 -o$cnt-le$best_cnt 444 then 445 best_strategy=$strategy 446 best_cnt=$cnt 447 fi 448 fi 449 continue 450 } 451 452 # Automerge succeeded. 453 result_tree=$(git write-tree)&& break 454done 455 456# If we have a resulting tree, that means the strategy module 457# auto resolved the merge cleanly. 458if test '' != "$result_tree" 459then 460 parents=$(git show-branch --independent "$head" "$@" | sed -e 's/^/-p /') 461 result_commit=$(printf '%s\n' "$merge_msg" | git commit-tree $result_tree $parents)|| exit 462 finish "$result_commit" "Merge made by$wt_strategy." 463 dropsave 464 exit 0 465fi 466 467# Pick the result from the best strategy and have the user fix it up. 468case "$best_strategy" in 469'') 470 restorestate 471 case "$use_strategies" in 472 ?*''?*) 473 echo >&2 "No merge strategy handled the merge." 474 ;; 475 *) 476 echo >&2 "Merge with strategy$use_strategiesfailed." 477 ;; 478 esac 479 exit 2 480 ;; 481"$wt_strategy") 482 # We already have its result in the working tree. 483 ;; 484*) 485 echo "Rewinding the tree to pristine..." 486 restorestate 487 echo "Using the$best_strategyto prepare resolving by hand." 488 git-merge-$best_strategy$common-- "$head_arg" "$@" 489 ;; 490esac 491 492if test "$squash" = t 493then 494 finish 495else 496 for remote 497 do 498 echo$remote 499 done >"$GIT_DIR/MERGE_HEAD" 500 printf '%s\n' "$merge_msg" >"$GIT_DIR/MERGE_MSG" 501fi 502 503if test "$merge_was_ok" = t 504then 505 echo >&2 \ 506 "Automatic merge went well; stopped before committing as requested" 507 exit 0 508else 509 { 510 echo ' 511Conflicts: 512' 513 git ls-files --unmerged | 514 sed -e 's/^[^ ]* / /' | 515 uniq 516 } >>"$GIT_DIR/MERGE_MSG" 517 git rerere 518 die "Automatic merge failed; fix conflicts and then commit the result." 519fi