fmt-merge-msg: fix off-by-one bug

[git.git] / git-am.sh

diff --git a/git-am.sh b/git-am.sh
index 04f01194356ea0c91a01eed682b068c15e313ee6..d0af786aec3f797943290cdc63fa77f393900160 100755 (executable)
--- a/git-am.sh
+++ b/git-am.sh
@@ -45,6 +45,12 @@ go_next () {
        this=$next
 }
 
+cannot_fallback () {
+       echo "$1"
+       echo "Cannot fall back to three-way merge."
+       exit 1
+}
+
 fall_back_3way () {
     O_OBJECT=`cd "$GIT_OBJECT_DIRECTORY" && pwd`
 
@@ -52,19 +58,23 @@ fall_back_3way () {
     mkdir "$dotest/patch-merge-tmp-dir"
 
     # First see if the patch records the index info that we can use.
-    if git-apply -z --index-info "$dotest/patch" \
-       >"$dotest/patch-merge-index-info" 2>/dev/null &&
-       GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
-       git-update-index -z --index-info <"$dotest/patch-merge-index-info" &&
-       GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
-       git-write-tree >"$dotest/patch-merge-base+" &&
-       # index has the base tree now.
-       GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
+    git-apply -z --index-info "$dotest/patch" \
+       >"$dotest/patch-merge-index-info" &&
+    GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
+    git-update-index -z --index-info <"$dotest/patch-merge-index-info" &&
+    GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
+    git-write-tree >"$dotest/patch-merge-base+" ||
+    cannot_fallback "Patch does not record usable index information."
+
+    echo Using index info to reconstruct a base tree...
+    if GIT_INDEX_FILE="$dotest/patch-merge-tmp-index" \
        git-apply $binary --cached <"$dotest/patch"
     then
-       echo Using index info to reconstruct a base tree...
        mv "$dotest/patch-merge-base+" "$dotest/patch-merge-base"
        mv "$dotest/patch-merge-tmp-index" "$dotest/patch-merge-index"
+    else
+        cannot_fallback "Did you hand edit your patch?
+It does not apply to blobs recorded in its index."
     fi
 
     test -f "$dotest/patch-merge-index" &&