Add --symmetricHEADmaster

Signed-off-by: Mattias Andrée <m@maandree.se>

39 files changed, 769 insertions, 11 deletions

diff --git a/t/all-positive-options-symmetric b/t/all-positive-options-symmetric
new file mode 100755
index 0000000..eb53cb9
--- /dev/null
+++ b/t/all-positive-options-symmetric
@@ -0,0 +1,23 @@
+#!/bin/sh -e
+. t/common.sh
+interactive
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	ours \
+	"${PARENT} base" \
+	same \
+	base \
+	"${TAIL}" \
+	same \
+	theirs \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same \
+	ours
+
+printf '%s' h > input
+normal --symmetric --remove-base --reduce --interactive file 8<input 9>output
+test -s output
diff --git a/t/combination-2-symmetric b/t/combination-2-symmetric
new file mode 100755
index 0000000..059897d
--- /dev/null
+++ b/t/combination-2-symmetric
@@ -0,0 +1,22 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	new \
+	"${PARENT} base" \
+	same \
+	old \
+	"${TAIL}" \
+	same \
+	new \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same \
+	new
+
+normal --symmetric --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/combination-remove-base-symmetric-reduce b/t/combination-remove-base-symmetric-reduce
new file mode 100755
index 0000000..c4b1cf9
--- /dev/null
+++ b/t/combination-remove-base-symmetric-reduce
@@ -0,0 +1,34 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	first \
+	"${PARENT} base" \
+	not-first \
+	"${TAIL}" \
+	first \
+	"${END} theirs" \
+	"${HEAD} ours" \
+	ours \
+	common \
+	"${PARENT} base" \
+	base \
+	common \
+	"${TAIL}" \
+	theirs \
+	common \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	first \
+	"${HEAD} ours" \
+	ours \
+	"${TAIL}" \
+	theirs \
+	"${END} theirs" \
+	common
+
+conflict --remove-base --symmetric --reduce file
+
+also_interactive yy
diff --git a/t/combination-symmetric-2-no-symmetric b/t/combination-symmetric-2-no-symmetric
new file mode 100755
index 0000000..6aaf0e0
--- /dev/null
+++ b/t/combination-symmetric-2-no-symmetric
@@ -0,0 +1,28 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	new \
+	"${PARENT} base" \
+	same \
+	old \
+	"${TAIL}" \
+	same \
+	new \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same \
+	"${HEAD} ours" \
+	new \
+	"${PARENT} base" \
+	old \
+	"${TAIL}" \
+	new \
+	"${END} theirs"
+
+conflict --symmetric --no-symmetric --no-symmetric file
+
+also_interactive r
diff --git a/t/combination-symmetric-reduce b/t/combination-symmetric-reduce
new file mode 100755
index 0000000..e5e370a
--- /dev/null
+++ b/t/combination-symmetric-reduce
@@ -0,0 +1,36 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	first \
+	"${PARENT} base" \
+	not-first \
+	"${TAIL}" \
+	first \
+	"${END} theirs" \
+	"${HEAD} ours" \
+	ours \
+	common \
+	"${PARENT} base" \
+	base \
+	common \
+	"${TAIL}" \
+	theirs \
+	common \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	first \
+	"${HEAD} ours" \
+	ours \
+	"${PARENT} base" \
+	base \
+	"${TAIL}" \
+	theirs \
+	"${END} theirs" \
+	common
+
+conflict --symmetric --reduce file
+
+also_interactive yr
diff --git a/t/common.sh b/t/common.sh
index 30e4b6e..38d2845 100644
--- a/t/common.sh
+++ b/t/common.sh
@@ -141,7 +141,7 @@ interactive_filename () {
 
 interactive_prompt () {
 	test $# = 2
-	printf '\e[1;34m(%s/%s) Resolve this conflict [h,t,b,m,r,e,s,d,q,?]? \e[0m\n' "$1" "$2"
+	printf '\e[1;34m(%s/%s) Resolve this conflict [h,t,b,m,y,r,e,s,d,q,?]? \e[0m\n' "$1" "$2"
 }
 
 interactive_help () {
@@ -155,6 +155,7 @@ interactive_help () {
 	fi
 	printf '%s\n' \
 		'm - merge' \
+		'y - select symmetric branches' \
 		'r - reduce' \
 		'e - manually edit this hunk' \
 		's - skip this hunk' \
diff --git a/t/invalid-option-combinations b/t/invalid-option-combinations
index 527ce63..1a75005 100755
--- a/t/invalid-option-combinations
+++ b/t/invalid-option-combinations
@@ -16,5 +16,54 @@ error --select-head --merge --select-tail file
 error --select-head --select-tail --merge file
 error --select-tail --merge --select-head file
 error --select-tail --select-head --merge file
+error --symmetric --merge file
+error --merge --symmetric file
+error --symmetric --select-head file
+error --select-head --symmetric file
+error --symmetric --select-tail file
+error --select-tail --symmetric file
+error --symmetric --merge --select-head file
+error --symmetric --select-head --merge file
+error --symmetric --merge --select-tail file
+error --symmetric --select-tail --merge file
+error --symmetric --select-head --select-tail file
+error --symmetric --select-tail --select-head file
+error --merge --symmetric --select-head file
+error --select-head --symmetric --merge file
+error --merge --symmetric --select-tail file
+error --select-tail --symmetric --merge file
+error --select-head --symmetric --select-tail file
+error --select-tail --symmetric --select-head file
+error --merge --select-head --symmetric file
+error --select-head --merge --symmetric file
+error --merge --select-tail --symmetric file
+error --select-tail --merge --symmetric file
+error --select-head --select-tail --symmetric file
+error --select-tail --select-head --symmetric file
+error --symmetric --merge --select-head --select-tail file
+error --symmetric --merge --select-tail --select-head file
+error --symmetric --select-head --merge --select-tail file
+error --symmetric --select-head --select-tail --merge file
+error --symmetric --select-tail --merge --select-head file
+error --symmetric --select-tail --select-head --merge file
+error --merge --symmetric --select-head --select-tail file
+error --merge --symmetric --select-tail --select-head file
+error --select-head --symmetric --merge --select-tail file
+error --select-head --symmetric --select-tail --merge file
+error --select-tail --symmetric --merge --select-head file
+error --select-tail --symmetric --select-head --merge file
+error --merge --select-head --symmetric --select-tail file
+error --merge --select-tail --symmetric --select-head file
+error --select-head --merge --symmetric --select-tail file
+error --select-head --select-tail --symmetric --merge file
+error --select-tail --merge --symmetric --select-head file
+error --select-tail --select-head --symmetric --merge file
+error --merge --select-head --select-tail --symmetric file
+error --merge --select-tail --select-head --symmetric file
+error --select-head --merge --select-tail --symmetric file
+error --select-head --select-tail --merge --symmetric file
+error --select-tail --merge --select-head --symmetric file
+error --select-tail --select-head --merge --symmetric file
+
 error --unknown-option file
 error '-$' file
diff --git a/t/no-option-merge b/t/no-option-merge
index 5f55d74..8f9a63e 100755
--- a/t/no-option-merge
+++ b/t/no-option-merge
@@ -4,23 +4,23 @@
 printf '%s\n' > file \
 	"${HEAD} ours" \
 	same \
-	ours \
+	new \
 	"${PARENT} base" \
 	same \
-	base \
+	old \
 	"${TAIL}" \
 	same \
-	theirs \
+	old \
 	"${END} theirs"
 
 printf '%s\n' > file.expected \
 	same \
 	"${HEAD} ours" \
-	ours \
+	new \
 	"${PARENT} base" \
-	base \
+	old \
 	"${TAIL}" \
-	theirs \
+	old \
 	"${END} theirs"
 
 conflict --no-merge file
diff --git a/t/no-option-merge-yes-no b/t/no-option-merge-yes-no
index f351e7c..af35ed8 100755
--- a/t/no-option-merge-yes-no
+++ b/t/no-option-merge-yes-no
@@ -3,11 +3,11 @@
 
 printf '%s\n' > file \
 	"${HEAD} ours" \
-	ours \
+	old \
 	"${PARENT} base" \
-	base \
+	old \
 	"${TAIL}" \
-	theirs \
+	new \
 	"${END} theirs"
 
 cp -- file file.expected
diff --git a/t/no-option-reduce-no-yes b/t/no-option-reduce-no-yes
index e6a7d8c..9078a9b 100755
--- a/t/no-option-reduce-no-yes
+++ b/t/no-option-reduce-no-yes
@@ -3,14 +3,25 @@
 
 printf '%s\n' > file \
 	"${HEAD} ours" \
+	same \
 	ours \
 	"${PARENT} base" \
+	same \
 	base \
 	"${TAIL}" \
+	same \
 	theirs \
 	"${END} theirs"
 
-cp -- file file.expected
+printf '%s\n' > file.expected \
+	same \
+	"${HEAD} ours" \
+	ours \
+	"${PARENT} base" \
+	base \
+	"${TAIL}" \
+	theirs \
+	"${END} theirs"
 
 conflict --no-reduce --reduce file
 
diff --git a/t/no-option-reduce-yes-no b/t/no-option-reduce-yes-no
index 82fa7bd..8a55b15 100755
--- a/t/no-option-reduce-yes-no
+++ b/t/no-option-reduce-yes-no
@@ -3,10 +3,13 @@
 
 printf '%s\n' > file \
 	"${HEAD} ours" \
+	same \
 	ours \
 	"${PARENT} base" \
+	same \
 	base \
 	"${TAIL}" \
+	same \
 	theirs \
 	"${END} theirs"
 
diff --git a/t/no-option-symmetric b/t/no-option-symmetric
new file mode 100755
index 0000000..82d6b73
--- /dev/null
+++ b/t/no-option-symmetric
@@ -0,0 +1,28 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	new \
+	"${PARENT} base" \
+	same \
+	old \
+	"${TAIL}" \
+	same \
+	new \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same \
+	"${HEAD} ours" \
+	new \
+	"${PARENT} base" \
+	old \
+	"${TAIL}" \
+	new \
+	"${END} theirs"
+
+conflict --no-symmetric file
+
+also_interactive r
diff --git a/t/no-option-symmetric-no-yes b/t/no-option-symmetric-no-yes
new file mode 100755
index 0000000..45954cb
--- /dev/null
+++ b/t/no-option-symmetric-no-yes
@@ -0,0 +1,18 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	new \
+	"${PARENT} base" \
+	old \
+	"${TAIL}" \
+	new \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	new
+
+normal --no-symmetric --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/no-option-symmetric-yes-no b/t/no-option-symmetric-yes-no
new file mode 100755
index 0000000..415467c
--- /dev/null
+++ b/t/no-option-symmetric-yes-no
@@ -0,0 +1,17 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} base" \
+	base \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-symmetric --no-reduce file
+
+also_interactive r
diff --git a/t/reduce-short-option b/t/reduce-short-option
new file mode 100755
index 0000000..0e2b5b7
--- /dev/null
+++ b/t/reduce-short-option
@@ -0,0 +1,26 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} 1" \
+	common-first \
+	head-second \
+	common-third \
+	"${TAIL} 2" \
+	common-first \
+	tail-second \
+	common-third \
+	"${END} 2"
+
+printf '%s\n' > file.expected \
+	common-first \
+	"${HEAD} 1" \
+	head-second \
+	"${TAIL} 2" \
+	tail-second \
+	"${END} 2" \
+	common-third
+
+conflict -r file
+
+also_interactive r
diff --git a/t/symmetric-1 b/t/symmetric-1
new file mode 100755
index 0000000..f0d1a4b
--- /dev/null
+++ b/t/symmetric-1
@@ -0,0 +1,11 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} only" \
+	only \
+	"${END} only"
+
+cp -- file file.expected
+
+error --symmetric --no-reduce file
diff --git a/t/symmetric-2-different b/t/symmetric-2-different
new file mode 100755
index 0000000..889e4ed
--- /dev/null
+++ b/t/symmetric-2-different
@@ -0,0 +1,15 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	ours \
+	"${TAIL}" \
+	theirs \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-2-identical b/t/symmetric-2-identical
new file mode 100755
index 0000000..90f8369
--- /dev/null
+++ b/t/symmetric-2-identical
@@ -0,0 +1,16 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-all-different b/t/symmetric-3-all-different
new file mode 100755
index 0000000..0693a80
--- /dev/null
+++ b/t/symmetric-3-all-different
@@ -0,0 +1,17 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	first \
+	"${PARENT} 2" \
+	second \
+	"${TAIL}" \
+	third \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-all-identical b/t/symmetric-3-all-identical
new file mode 100755
index 0000000..986d367
--- /dev/null
+++ b/t/symmetric-3-all-identical
@@ -0,0 +1,18 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-different-base b/t/symmetric-3-different-base
new file mode 100755
index 0000000..176c212
--- /dev/null
+++ b/t/symmetric-3-different-base
@@ -0,0 +1,18 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	different \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-different-head b/t/symmetric-3-different-head
new file mode 100755
index 0000000..435d828
--- /dev/null
+++ b/t/symmetric-3-different-head
@@ -0,0 +1,17 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	different \
+	"${PARENT} 2" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-different-tail b/t/symmetric-3-different-tail
new file mode 100755
index 0000000..733c7d3
--- /dev/null
+++ b/t/symmetric-3-different-tail
@@ -0,0 +1,17 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${TAIL}" \
+	different \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-empty-head b/t/symmetric-3-empty-head
new file mode 100755
index 0000000..af61802
--- /dev/null
+++ b/t/symmetric-3-empty-head
@@ -0,0 +1,16 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	"${PARENT} 2" \
+	2 \
+	"${TAIL}" \
+	2 \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-empty-head-tail b/t/symmetric-3-empty-head-tail
new file mode 100755
index 0000000..f93cd84
--- /dev/null
+++ b/t/symmetric-3-empty-head-tail
@@ -0,0 +1,15 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	"${PARENT} 2" \
+	base \
+	"${TAIL}" \
+	"${END} theirs"
+
+: > file.expected
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-3-empty-tail b/t/symmetric-3-empty-tail
new file mode 100755
index 0000000..bbd4e7a
--- /dev/null
+++ b/t/symmetric-3-empty-tail
@@ -0,0 +1,16 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	1 \
+	"${PARENT} 2" \
+	1 \
+	"${TAIL}" \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-different-head b/t/symmetric-4-different-head
new file mode 100755
index 0000000..0d4d704
--- /dev/null
+++ b/t/symmetric-4-different-head
@@ -0,0 +1,19 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	different \
+	"${PARENT} 2" \
+	same \
+	"${PARENT} 3" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-different-lower-middle b/t/symmetric-4-different-lower-middle
new file mode 100755
index 0000000..f8c334e
--- /dev/null
+++ b/t/symmetric-4-different-lower-middle
@@ -0,0 +1,19 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${PARENT} 3" \
+	different \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-different-tail b/t/symmetric-4-different-tail
new file mode 100755
index 0000000..1bf80ff
--- /dev/null
+++ b/t/symmetric-4-different-tail
@@ -0,0 +1,19 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${PARENT} 3" \
+	same \
+	"${TAIL}" \
+	different \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-different-upper-middle b/t/symmetric-4-different-upper-middle
new file mode 100755
index 0000000..d78a5a2
--- /dev/null
+++ b/t/symmetric-4-different-upper-middle
@@ -0,0 +1,19 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	different \
+	"${PARENT} 3" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-identical b/t/symmetric-4-identical
new file mode 100755
index 0000000..40c82d7
--- /dev/null
+++ b/t/symmetric-4-identical
@@ -0,0 +1,20 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${PARENT} 3" \
+	same \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-same-different-middles b/t/symmetric-4-same-different-middles
new file mode 100755
index 0000000..9d95e43
--- /dev/null
+++ b/t/symmetric-4-same-different-middles
@@ -0,0 +1,25 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	new \
+	new \
+	"${PARENT} 2" \
+	old \
+	old \
+	"${PARENT} 3" \
+	old \
+	old \
+	"${TAIL}" \
+	new \
+	new \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	new \
+	new
+
+normal --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-4-unique-different-middles b/t/symmetric-4-unique-different-middles
new file mode 100755
index 0000000..1b76187
--- /dev/null
+++ b/t/symmetric-4-unique-different-middles
@@ -0,0 +1,23 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	common \
+	first \
+	common \
+	"${PARENT} 3" \
+	common \
+	second \
+	common \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-5-different-lower-middle b/t/symmetric-5-different-lower-middle
new file mode 100755
index 0000000..530ea01
--- /dev/null
+++ b/t/symmetric-5-different-lower-middle
@@ -0,0 +1,21 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	same \
+	"${PARENT} 3" \
+	same \
+	"${PARENT} 4" \
+	different \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-5-different-upper-middle b/t/symmetric-5-different-upper-middle
new file mode 100755
index 0000000..b2fe2dd
--- /dev/null
+++ b/t/symmetric-5-different-upper-middle
@@ -0,0 +1,21 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} 2" \
+	different \
+	"${PARENT} 3" \
+	add \
+	"${PARENT} 4" \
+	add \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- file file.expected
+
+conflict --symmetric --no-reduce file
+
+also_interactive y
diff --git a/t/symmetric-multiple-conflicts b/t/symmetric-multiple-conflicts
new file mode 100755
index 0000000..713a96c
--- /dev/null
+++ b/t/symmetric-multiple-conflicts
@@ -0,0 +1,42 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	before \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} base" \
+	different-interior \
+	"${TAIL}" \
+	same \
+	"${END} theirs" \
+	between \
+	"${HEAD} ours" \
+	different-head \
+	"${PARENT} base" \
+	interior \
+	"${PARENT} other" \
+	interior \
+	"${TAIL}" \
+	same \
+	"${END} theirs" \
+	after
+
+printf '%s\n' > file.expected \
+	before \
+	same \
+	between \
+	"${HEAD} ours" \
+	different-head \
+	"${PARENT} base" \
+	interior \
+	"${PARENT} other" \
+	interior \
+	"${TAIL}" \
+	same \
+	"${END} theirs" \
+	after
+
+conflict --symmetric --no-reduce file
+
+also_interactive yy
diff --git a/t/symmetric-multiple-files b/t/symmetric-multiple-files
new file mode 100755
index 0000000..86d2235
--- /dev/null
+++ b/t/symmetric-multiple-files
@@ -0,0 +1,29 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > first \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} base" \
+	different \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > first.expected \
+	same
+
+printf '%s\n' > second \
+	"${HEAD} ours" \
+	different \
+	"${PARENT} base" \
+	interior \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+cp -- second second.expected
+
+conflict --symmetric --no-reduce first second
+
+also_interactive yy
diff --git a/t/symmetric-no-conflicts b/t/symmetric-no-conflicts
new file mode 100755
index 0000000..d7c8c7f
--- /dev/null
+++ b/t/symmetric-no-conflicts
@@ -0,0 +1,11 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	no conflicts in this file
+
+cp -- file file.expected
+
+normal --symmetric --no-reduce file
+
+also_interactive ''
diff --git a/t/symmetric-short-option b/t/symmetric-short-option
new file mode 100755
index 0000000..66c257a
--- /dev/null
+++ b/t/symmetric-short-option
@@ -0,0 +1,18 @@
+#!/bin/sh -e
+. t/common.sh
+
+printf '%s\n' > file \
+	"${HEAD} ours" \
+	same \
+	"${PARENT} base" \
+	different \
+	"${TAIL}" \
+	same \
+	"${END} theirs"
+
+printf '%s\n' > file.expected \
+	same
+
+normal -y --no-reduce file
+
+also_interactive y