diff-hunk-header-re
diff-hunk-header-re is a variable defined in `diff-mode.el'.
Its value is
"^\\(?:^@@ -\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)? \\+\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)? @@.*\\|\\*\\{15\\}.*\n\\*\\*\\* .+ \\*\\*\\*\\*\\|[0-9]+\\(,[0-9]+\\)?[acd][0-9]+\\(,[0-9]+\\)?\\)$"
- This variable may be risky if used as a file-local variable.