[PATCH] userdiff: support Python async functions

[Josh Holland <anowlcalledjosh@gmail.com>]

Python's async functions (declared with "async def" rather than "def")
were not being displayed in hunk headers. This commit teaches git about
the async function syntax, and adds tests for the Python userdiff regex.

Signed-off-by: Josh Holland <anowlcalledjosh@gmail.com>
---
 t/t4018/python-async-def | 4 ++++
 t/t4018/python-class     | 4 ++++
 t/t4018/python-def       | 4 ++++
 userdiff.c               | 2 +-
 4 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 t/t4018/python-async-def
 create mode 100644 t/t4018/python-class
 create mode 100644 t/t4018/python-def

diff --git a/t/t4018/python-async-def b/t/t4018/python-async-def
new file mode 100644
index 000000000..87640e03d
--- /dev/null
+++ b/t/t4018/python-async-def
@@ -0,0 +1,4 @@
+async def RIGHT(pi: int = 3.14):
+    while True:
+        break
+    return ChangeMe()
diff --git a/t/t4018/python-class b/t/t4018/python-class
new file mode 100644
index 000000000..ba9e74143
--- /dev/null
+++ b/t/t4018/python-class
@@ -0,0 +1,4 @@
+class RIGHT(int, str):
+    # comment
+    # another comment
+    # ChangeMe
diff --git a/t/t4018/python-def b/t/t4018/python-def
new file mode 100644
index 000000000..e50b31b0a
--- /dev/null
+++ b/t/t4018/python-def
@@ -0,0 +1,4 @@
+def RIGHT(pi: int = 3.14):
+    while True:
+        break
+    return ChangeMe()
diff --git a/userdiff.c b/userdiff.c
index e74a6d402..057fdcc55 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -124,7 +124,7 @@ PATTERNS("php",
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
 	 "|[-+*/<>%&^|=!.]=|--|\\+\\+|<<=?|>>=?|===|&&|\\|\\||::|->"),
-PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
+PATTERNS("python", "^[ \t]*((class|(async[ \t]+)?def)[ \t].*)$",
 	 /* -- */
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
-- 
2.24.0