Use symbolic name SHORT_NAME_AMBIGUOUS as error return value

[thirdparty/git.git] / git-applypatch.sh

diff --git a/git-applypatch.sh b/git-applypatch.sh
index 9f5a45bb2bbb330207ea4410a76f5521bdc7b850..12cab1e0d4ceb1f1c58c418f96358b252713bf58 100755 (executable)
--- a/git-applypatch.sh
+++ b/git-applypatch.sh
@@ -10,7 +10,11 @@
 ##     $3 - "info" file with Author, email and subject
 ##     $4 - optional file containing signoff to add
 ##
-. git-sh-setup || die "Not a git archive."
+
+USAGE='<msg> <patch> <info> [<signoff>]'
+. git-sh-setup
+
+case "$#" in 3|4) ;; *) usage ;; esac
 
 final=.dotest/final-commit
 ##
@@ -22,6 +26,8 @@ query_apply=.dotest/.query_apply
 ## if this file exists.
 keep_subject=.dotest/.keep_subject
 
+## We do not attempt the 3-way merge fallback unless this file exists.
+fall_back_3way=.dotest/.3way
 
 MSGFILE=$1
 PATCHFILE=$2
@@ -29,10 +35,10 @@ INFO=$3
 SIGNOFF=$4
 EDIT=${VISUAL:-${EDITOR:-vi}}
 
-export GIT_AUTHOR_NAME="$(sed -n '/^Author/ s/Author: //p' .dotest/info)"
-export GIT_AUTHOR_EMAIL="$(sed -n '/^Email/ s/Email: //p' .dotest/info)"
-export GIT_AUTHOR_DATE="$(sed -n '/^Date/ s/Date: //p' .dotest/info)"
-export SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' .dotest/info)"
+export GIT_AUTHOR_NAME="$(sed -n '/^Author/ s/Author: //p' "$INFO")"
+export GIT_AUTHOR_EMAIL="$(sed -n '/^Email/ s/Email: //p' "$INFO")"
+export GIT_AUTHOR_DATE="$(sed -n '/^Date/ s/Date: //p' "$INFO")"
+export SUBJECT="$(sed -n '/^Subject/ s/Subject: //p' "$INFO")"
 
 if test '' != "$SIGNOFF"
 then
@@ -54,8 +60,10 @@ then
                        sed -ne '/^Signed-off-by: /p' "$MSGFILE" |
                        tail -n 1
                `
-               test "$LAST_SIGNED_OFF_BY" = "$SIGNOFF" ||
-               echo "$SIGNOFF" >>"$MSGFILE"
+               test "$LAST_SIGNED_OFF_BY" = "$SIGNOFF" || {
+                   test '' = "$LAST_SIGNED_OFF_BY" && echo
+                   echo "$SIGNOFF"
+               } >>"$MSGFILE"
        fi
 fi
 
@@ -79,7 +87,7 @@ while [ "$interactive" = yes ]; do
        echo "--------------------------"
        cat "$final"
        echo "--------------------------"
-       echo -n "Apply? [y]es/[n]o/[e]dit/[a]ccept all "
+       printf "Apply? [y]es/[n]o/[e]dit/[a]ccept all "
        read reply
        case "$reply" in
                y|Y) interactive=no;;
@@ -99,7 +107,92 @@ echo
 echo Applying "'$SUBJECT'"
 echo
 
-git-apply --index "$PATCHFILE" || exit 1
+git-apply --index "$PATCHFILE" || {
+
+       # git-apply exits with status 1 when the patch does not apply,
+       # but it die()s with other failures, most notably upon corrupt
+       # patch.  In the latter case, there is no point to try applying
+       # it to another tree and do 3-way merge.
+       test $? = 1 || exit 1
+
+       test -f "$fall_back_3way" || exit 1
+
+       # Here if we know which revision the patch applies to,
+       # we create a temporary working tree and index, apply the
+       # patch, and attempt 3-way merge with the resulting tree.
+
+       O_OBJECT=`cd "$GIT_OBJECT_DIRECTORY" && pwd`
+       rm -fr .patch-merge-*
+
+       if git-apply -z --index-info "$PATCHFILE" \
+               >.patch-merge-index-info 2>/dev/null &&
+               GIT_INDEX_FILE=.patch-merge-tmp-index \
+               git-update-index -z --index-info <.patch-merge-index-info &&
+               GIT_INDEX_FILE=.patch-merge-tmp-index \
+               git-write-tree >.patch-merge-tmp-base &&
+               (
+                       mkdir .patch-merge-tmp-dir &&
+                       cd .patch-merge-tmp-dir &&
+                       GIT_INDEX_FILE="../.patch-merge-tmp-index" \
+                       GIT_OBJECT_DIRECTORY="$O_OBJECT" \
+                       git-apply $binary --index
+               ) <"$PATCHFILE"
+       then
+               echo Using index info to reconstruct a base tree...
+               mv .patch-merge-tmp-base .patch-merge-base
+               mv .patch-merge-tmp-index .patch-merge-index
+       else
+       (
+               N=10
+
+               # Otherwise, try nearby trees that can be used to apply the
+               # patch.
+               git-rev-list --max-count=$N HEAD
+
+               # or hoping the patch is against known tags...
+               git-ls-remote --tags .
+       ) |
+           while read base junk
+           do
+               # Try it if we have it as a tree.
+               git-cat-file tree "$base" >/dev/null 2>&1 || continue
+
+               rm -fr .patch-merge-tmp-* &&
+               mkdir .patch-merge-tmp-dir || break
+               (
+                       cd .patch-merge-tmp-dir &&
+                       GIT_INDEX_FILE=../.patch-merge-tmp-index &&
+                       GIT_OBJECT_DIRECTORY="$O_OBJECT" &&
+                       export GIT_INDEX_FILE GIT_OBJECT_DIRECTORY &&
+                       git-read-tree "$base" &&
+                       git-apply --index &&
+                       mv ../.patch-merge-tmp-index ../.patch-merge-index &&
+                       echo "$base" >../.patch-merge-base
+               ) <"$PATCHFILE"  2>/dev/null && break
+           done
+       fi
+
+       test -f .patch-merge-index &&
+       his_tree=$(GIT_INDEX_FILE=.patch-merge-index git-write-tree) &&
+       orig_tree=$(cat .patch-merge-base) &&
+       rm -fr .patch-merge-* || exit 1
+
+       echo Falling back to patching base and 3-way merge using $orig_tree...
+
+       # This is not so wrong.  Depending on which base we picked,
+       # orig_tree may be wildly different from ours, but his_tree
+       # has the same set of wildly different changes in parts the
+       # patch did not touch, so resolve ends up cancelling them,
+       # saying that we reverted all those changes.
+
+       if git-merge-resolve $orig_tree -- HEAD $his_tree
+       then
+               echo Done.
+       else
+               echo Failed to merge in the changes.
+               exit 1
+       fi
+}
 
 if test -x "$GIT_DIR"/hooks/pre-applypatch
 then