diff --git a/hgmerge b/hgmerge
--- a/hgmerge
+++ b/hgmerge
@@ -37,20 +37,45 @@ type $FILEMERGE >/dev/null 2>&1 || FILEM
 type $KDIFF3    >/dev/null 2>&1 || KDIFF3=
 type $TKDIFF    >/dev/null 2>&1 || TKDIFF=
 
+# temporary directory for diff+patch merge
+HGTMP="${TMPDIR-/tmp}/hgmerge.$RANDOM.$RANDOM.$RANDOM.$$"
+
+# put all your required cleanup here
+cleanup() {
+    rm -f "$LOCAL.orig"
+    rm -rf "$HGTMP"
+}
+
+# functions concerning program exit
+success() {
+    cleanup
+    exit 0
+}
+
+failure() {
+    echo "merge failed" 1>&2
+    cp "$LOCAL.orig" "$LOCAL"
+    cleanup
+    exit 1
+}
+
+# Clean up when interrupted
+trap "failure" 1 2 3 6 15 # HUP INT QUIT ABRT TERM
+
 # Back up our file
 cp "$LOCAL" "$LOCAL.orig"
 
 # Attempt to do a non-interactive merge
 if [ -n "$MERGE" ]; then
-    $MERGE "$LOCAL" "$BASE" "$OTHER" 2> /dev/null && exit 0
+    $MERGE "$LOCAL" "$BASE" "$OTHER" 2> /dev/null && success
     cp "$LOCAL.orig" "$LOCAL"
 elif [ -n "$DIFF3" ]; then
     echo $DIFF3 -m "$LOCAL.orig" "$BASE" "$OTHER"
-    $DIFF3 -m "$LOCAL.orig" "$BASE" "$OTHER" > "$LOCAL" && exit 0
+    $DIFF3 -m "$LOCAL.orig" "$BASE" "$OTHER" > "$LOCAL" && success
     if [ $? -eq 2 ]; then
         echo "$DIFF3 failed! Exiting." 1>&2
         cp "$LOCAL.orig" "$LOCAL"
-        exit 1
+        failure
     fi
     cp "$LOCAL.orig" "$LOCAL"
 fi
@@ -65,12 +90,12 @@ if [ -n "$FILEMERGE" ]; then
     if ! "$FILEMERGE" -left "$OTHER" -right "$LOCAL" -ancestor "$BASE" -merge "$LOCAL"
     then
         echo "FileMerge failed to launch"
-        exit 1
+        failure
     fi
     if ! test "$LOCAL" -ef "$LOCAL.link"
     then
         rm "$LOCAL.orig" "$LOCAL.link"
-        exit 0
+        success
     else
         rm "$LOCAL.link"
         echo "$LOCAL is unchanged. Was the merge successful?"
@@ -79,26 +104,26 @@ if [ -n "$FILEMERGE" ]; then
             if test "$answer" == "yes"
             then
                 rm "$LOCAL.orig"
-                exit 0
+                success
             else
-                exit 1
+                failure
             fi
         done
-        exit 1
+        failure
     fi
 fi
 
 if [ -n "$DISPLAY" ]; then
     # try using kdiff3, which is fairly nice
     if [ -n "$KDIFF3" ]; then
-	$KDIFF3 --auto "$BASE" "$LOCAL" "$OTHER" -o "$LOCAL" || exit 1
-	exit 0
+	$KDIFF3 --auto "$BASE" "$LOCAL" "$OTHER" -o "$LOCAL" || failure
+	success
     fi
 
     # try using tkdiff, which is a bit less sophisticated
     if [ -n "$TKDIFF" ]; then
-	$TKDIFF "$LOCAL" "$OTHER" -a "$BASE" -o "$LOCAL" || exit 1
-	exit 0
+	$TKDIFF "$LOCAL" "$OTHER" -a "$BASE" -o "$LOCAL" || failure
+	success
     fi
 fi
 
@@ -106,7 +131,7 @@ fi
 if [ -n "$MERGE" ]; then
     echo "conflicts detected in $LOCAL"
     $MERGE "$LOCAL" "$BASE" "$OTHER" 2>/dev/null || $EDITOR "$LOCAL"
-    exit 0
+    success
 fi
 
 if [ -n "$DIFF3" ]; then
@@ -117,38 +142,29 @@ if [ -n "$DIFF3" ]; then
                 $EDITOR "$LOCAL" ;;
             2)  echo "$DIFF3 failed! Exiting." 1>&2
                 cp "$LOCAL.orig" "$LOCAL"
-                exit 1 ;;
+                failure ;;
         esac
-        exit 0
+        success
     }
 fi
 
-HGTMP=""
-cleanup_exit() {
-    rm -rf "$HGTMP"
-}
-
 # attempt to manually merge with diff and patch
 if [ -n "$DIFF" -a -n "$PATCH" ]; then
-    # Remove temporary files even if we get interrupted
-    trap "cleanup_exit" 0 # normal exit
-    trap "exit 1" 1 2 3 6 15 # HUP INT QUIT ABRT TERM
 
-    HGTMP="${TMPDIR-/tmp}/hgmerge.$RANDOM.$RANDOM.$RANDOM.$$"
     (umask 077 && mkdir "$HGTMP") || {
-	echo "Could not create temporary directory! Exiting." 1>&2
-	exit 1
+	echo "Could not create temporary directory $HGTMP" 1>&2
+	failure
     }
 
     $DIFF -u "$BASE" "$OTHER" > "$HGTMP/diff" || :
     if $PATCH "$LOCAL" < "$HGTMP/diff"; then
-	exit 0
+	success
     else
 	# If rejects are empty after using the editor, merge was ok
-	$EDITOR "$LOCAL" "$LOCAL.rej" && test -s "$LOCAL.rej" || exit 0
+	$EDITOR "$LOCAL" "$LOCAL.rej" && test -s "$LOCAL.rej" || success
     fi
-    exit 1
+    failure
 fi
 
 echo "hgmerge: unable to find merge, tkdiff, kdiff3, or diff+patch!"
-exit 1
+failure