Merge branch 'rs/include-comments-before-the-function-header'

"git grep -W", "git diff -W" and their friends learned a heuristic
to extend a pre-context beyond the line that matches the "function
pattern" (aka "diff.*.xfuncname") to include a comment block, if
exists, that immediately precedes it.

* rs/include-comments-before-the-function-header:
  grep: show non-empty lines before functions with -W
  grep: update boundary variable for pre-context
  t7810: improve check of -W with user-defined function lines
  xdiff: show non-empty lines before functions with -W
  xdiff: factor out is_func_rec()
  t4051: add test for comments preceding function lines

3 files changed, 38 insertions, 10 deletions

diff --git a/t/t4051-diff-function-context.sh b/t/t4051-diff-function-context.sh
index 3e6b485ecb..2d76a971c4 100755
--- a/t/t4051-diff-function-context.sh
+++ b/t/t4051-diff-function-context.sh
@@ -85,6 +85,10 @@ test_expect_success 'setup' '
 
 check_diff changed_hello 'changed function'
 
+test_expect_success ' context includes comment' '
+	grep "^ .*Hello comment" changed_hello.diff
+'
+
 test_expect_success ' context includes begin' '
 	grep "^ .*Begin of hello" changed_hello.diff
 '
diff --git a/t/t4051/hello.c b/t/t4051/hello.c
index 63b1a1e4ef..73e767e178 100644
--- a/t/t4051/hello.c
+++ b/t/t4051/hello.c
@@ -1,4 +1,7 @@
 
+/*
+ * Hello comment.
+ */
 static void hello(void)	// Begin of hello
 {
 	/*
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 2a6679c2f5..c02ca735b9 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -60,6 +60,18 @@ test_expect_success setup '
 		echo " line with leading space3"
 		echo "line without leading space2"
 	} >space &&
+	cat >hello.ps1 <<-\EOF &&
+	# No-op.
+	function dummy() {}
+
+	# Say hello.
+	function hello() {
+	  echo "Hello world."
+	} # hello
+
+	# Still a no-op.
+	function dummy() {}
+	EOF
 	git add . &&
 	test_tick &&
 	git commit -m initial
@@ -766,18 +778,27 @@ test_expect_success 'grep -W shows no trailing empty lines' '
 	test_cmp expected actual
 '
 
-cat >expected <<EOF
-hello.c=	printf("Hello world.\n");
-hello.c:	return 0;
-hello.c-	/* char ?? */
-EOF
-
 test_expect_success 'grep -W with userdiff' '
 	test_when_finished "rm -f .gitattributes" &&
-	git config diff.custom.xfuncname "(printf.*|})$" &&
-	echo "hello.c diff=custom" >.gitattributes &&
-	git grep -W return >actual &&
-	test_cmp expected actual
+	git config diff.custom.xfuncname "^function .*$" &&
+	echo "hello.ps1 diff=custom" >.gitattributes &&
+	git grep -W echo >function-context-userdiff-actual
+'
+
+test_expect_success ' includes preceding comment' '
+	grep "# Say hello" function-context-userdiff-actual
+'
+
+test_expect_success ' includes function line' '
+	grep "=function hello" function-context-userdiff-actual
+'
+
+test_expect_success ' includes matching line' '
+	grep ":  echo" function-context-userdiff-actual
+'
+
+test_expect_success ' includes last line of the function' '
+	grep "} # hello" function-context-userdiff-actual
 '
 
 for threads in $(test_seq 0 10)