Merge pull request libgit2#4451 from libgit2/charliesome/trailer-info

Implement message trailer parsing API

Author: brianmario

include/git2/message.h

@@ -38,6 +38,47 @@ GIT_BEGIN_DECL
  */
 GIT_EXTERN(int) git_message_prettify(git_buf *out, const char *message, int strip_comments, char comment_char);
 
+/**
+ * Represents a single git message trailer.
+ */
+typedef struct {
+  const char *key;
+  const char *value;
+} git_message_trailer;
+
+/**
+ * Represents an array of git message trailers.
+ *
+ * Struct members under the private comment are private, subject to change
+ * and should not be used by callers.
+ */
+typedef struct {
+  git_message_trailer *trailers;
+  size_t count;
+
+  /* private */
+  char *_trailer_block;
+} git_message_trailer_array;
+
+/**
+ * Parse trailers out of a message, filling the array pointed to by +arr+.
+ *
+ * Trailers are key/value pairs in the last paragraph of a message, not
+ * including any patches or conflicts that may be present.
+ *
+ * @param arr A pre-allocated git_message_trailer_array struct to be filled in
+ *            with any trailers found during parsing.
+ * @param message The message to be parsed
+ * @return 0 on success, or non-zero on error.
+ */
+GIT_EXTERN(int) git_message_trailers(git_message_trailer_array *arr, const char *message);
+
+/**
+ * Clean's up any allocated memory in the git_message_trailer_array filled by
+ * a call to git_message_trailers.
+ */
+GIT_EXTERN(void) git_message_trailer_array_free(git_message_trailer_array *arr);
+
 /** @} */
 GIT_END_DECL