merge(3p/git): Merge git upstream at v2.26.2

third_party/git/merge-recursive.h

@@ -1,104 +1,124 @@
 #ifndef MERGE_RECURSIVE_H
 #define MERGE_RECURSIVE_H
 
-#include "string-list.h"
-#include "unpack-trees.h"
+#include "strbuf.h"
 
 struct commit;
-
+struct commit_list;
+struct object_id;
 struct repository;
+struct tree;
 
+struct merge_options_internal;
 struct merge_options {
+	struct repository *repo;
+
+	/* ref names used in console messages and conflict markers */
 	const char *ancestor;
 	const char *branch1;
 	const char *branch2;
+
+	/* rename related options */
+	int detect_renames;
 	enum {
-		MERGE_RECURSIVE_NORMAL = 0,
-		MERGE_RECURSIVE_OURS,
-		MERGE_RECURSIVE_THEIRS
-	} recursive_variant;
-	const char *subtree_shift;
-	unsigned buffer_output; /* 1: output at end, 2: keep buffered */
-	unsigned renormalize : 1;
-	long xdl_opts;
-	int verbosity;
-	int detect_directory_renames;
-	int diff_detect_rename;
-	int merge_detect_rename;
-	int diff_rename_limit;
-	int merge_rename_limit;
+		MERGE_DIRECTORY_RENAMES_NONE = 0,
+		MERGE_DIRECTORY_RENAMES_CONFLICT = 1,
+		MERGE_DIRECTORY_RENAMES_TRUE = 2
+	} detect_directory_renames;
+	int rename_limit;
 	int rename_score;
-	int needed_rename_limit;
 	int show_rename_progress;
-	int call_depth;
-	struct strbuf obuf;
-	struct hashmap current_file_dir_set;
-	struct string_list df_conflict_file_set;
-	struct unpack_trees_options unpack_opts;
-	struct index_state orig_index;
-	struct repository *repo;
+
+	/* xdiff-related options (patience, ignore whitespace, ours/theirs) */
+	long xdl_opts;
+	enum {
+		MERGE_VARIANT_NORMAL = 0,
+		MERGE_VARIANT_OURS,
+		MERGE_VARIANT_THEIRS
+	} recursive_variant;
+
+	/* console output related options */
+	int verbosity;
+	unsigned buffer_output; /* 1: output at end, 2: keep buffered */
+	struct strbuf obuf;     /* output buffer; if buffer_output == 2, caller
+				 * must handle and call strbuf_release */
+
+	/* miscellaneous control options */
+	const char *subtree_shift;
+	unsigned renormalize : 1;
+
+	/* internal fields used by the implementation */
+	struct merge_options_internal *priv;
 };
 
+void init_merge_options(struct merge_options *opt, struct repository *repo);
+
+/* parse the option in s and update the relevant field of opt */
+int parse_merge_opt(struct merge_options *opt, const char *s);
+
 /*
- * For dir_rename_entry, directory names are stored as a full path from the
- * toplevel of the repository and do not include a trailing '/'.  Also:
- *
- *   dir:                original name of directory being renamed
- *   non_unique_new_dir: if true, could not determine new_dir
- *   new_dir:            final name of directory being renamed
- *   possible_new_dirs:  temporary used to help determine new_dir; see comments
- *                       in get_directory_renames() for details
+ * RETURN VALUES: All the merge_* functions below return a value as follows:
+ *   > 0     Merge was clean
+ *   = 0     Merge had conflicts
+ *   < 0     Merge hit an unexpected and unrecoverable problem (e.g. disk
+ *             full) and aborted merge part-way through.
  */
-struct dir_rename_entry {
-	struct hashmap_entry ent; /* must be the first member! */
-	char *dir;
-	unsigned non_unique_new_dir:1;
-	struct strbuf new_dir;
-	struct string_list possible_new_dirs;
-};
 
-struct collision_entry {
-	struct hashmap_entry ent; /* must be the first member! */
-	char *target_file;
-	struct string_list source_files;
-	unsigned reported_already:1;
-};
-
-static inline int merge_detect_rename(struct merge_options *o)
-{
-	return o->merge_detect_rename >= 0 ? o->merge_detect_rename :
-		o->diff_detect_rename >= 0 ? o->diff_detect_rename : 1;
-}
-
-/* merge_trees() but with recursive ancestor consolidation */
-int merge_recursive(struct merge_options *o,
-		    struct commit *h1,
-		    struct commit *h2,
-		    struct commit_list *ancestors,
-		    struct commit **result);
-
-/* rename-detecting three-way merge, no recursion */
-int merge_trees(struct merge_options *o,
+/*
+ * rename-detecting three-way merge, no recursion.
+ *
+ * Outputs:
+ *   - See RETURN VALUES above
+ *   - No commit is created
+ *   - opt->repo->index has the new index
+ *   - $GIT_INDEX_FILE is not updated
+ *   - The working tree is updated with results of the merge
+ */
+int merge_trees(struct merge_options *opt,
 		struct tree *head,
 		struct tree *merge,
-		struct tree *common,
-		struct tree **result);
+		struct tree *merge_base);
 
 /*
- * "git-merge-recursive" can be fed trees; wrap them into
- * virtual commits and call merge_recursive() proper.
+ * merge_recursive is like merge_trees() but with recursive ancestor
+ * consolidation and, if the commit is clean, creation of a commit.
+ *
+ * NOTE: empirically, about a decade ago it was determined that with more
+ *       than two merge bases, optimal behavior was found when the
+ *       merge_bases were passed in the order of oldest commit to newest
+ *       commit.  Also, merge_bases will be consumed (emptied) so make a
+ *       copy if you need it.
+ *
+ * Outputs:
+ *   - See RETURN VALUES above
+ *   - If merge is clean, a commit is created and its address written to *result
+ *   - opt->repo->index has the new index
+ *   - $GIT_INDEX_FILE is not updated
+ *   - The working tree is updated with results of the merge
  */
-int merge_recursive_generic(struct merge_options *o,
+int merge_recursive(struct merge_options *opt,
+		    struct commit *h1,
+		    struct commit *h2,
+		    struct commit_list *merge_bases,
+		    struct commit **result);
+
+/*
+ * merge_recursive_generic can operate on trees instead of commits, by
+ * wrapping the trees into virtual commits, and calling merge_recursive().
+ * It also writes out the in-memory index to disk if the merge is successful.
+ *
+ * Outputs:
+ *   - See RETURN VALUES above
+ *   - If merge is clean, a commit is created and its address written to *result
+ *   - opt->repo->index has the new index
+ *   - $GIT_INDEX_FILE is updated
+ *   - The working tree is updated with results of the merge
+ */
+int merge_recursive_generic(struct merge_options *opt,
 			    const struct object_id *head,
 			    const struct object_id *merge,
-			    int num_ca,
-			    const struct object_id **ca,
+			    int num_merge_bases,
+			    const struct object_id **merge_bases,
 			    struct commit **result);
 
-void init_merge_options(struct merge_options *o,
-			struct repository *repo);
-struct tree *write_tree_from_memory(struct merge_options *o);
-
-int parse_merge_opt(struct merge_options *out, const char *s);
-
 #endif