Merge branch 'ab/plug-leak-in-revisions'

Plug the memory leaks from the trickiest API of all, the revision
walker.

* ab/plug-leak-in-revisions: (27 commits)
  revisions API: add a TODO for diff_free(&revs->diffopt)
  revisions API: have release_revisions() release "topo_walk_info"
  revisions API: have release_revisions() release "date_mode"
  revisions API: call diff_free(&revs->pruning) in revisions_release()
  revisions API: release "reflog_info" in release revisions()
  revisions API: clear "boundary_commits" in release_revisions()
  revisions API: have release_revisions() release "prune_data"
  revisions API: have release_revisions() release "grep_filter"
  revisions API: have release_revisions() release "filter"
  revisions API: have release_revisions() release "cmdline"
  revisions API: have release_revisions() release "mailmap"
  revisions API: have release_revisions() release "commits"
  revisions API users: use release_revisions() for "prune_data" users
  revisions API users: use release_revisions() with UNLEAK()
  revisions API users: use release_revisions() in builtin/log.c
  revisions API users: use release_revisions() in http-push.c
  revisions API users: add "goto cleanup" for release_revisions()
  stash: always have the owner of "stash_info" free it
  revisions API users: use release_revisions() needing REV_INFO_INIT
  revision.[ch]: document and move code declared around "init"
  ...

1 files changed, 48 insertions, 25 deletions

diff --git a/revision.h b/revision.h
index e80c148b19..e576845cdd 100644
--- a/revision.h
+++ b/revision.h
@@ -330,31 +330,24 @@ struct rev_info {
 	struct tmp_objdir *remerge_objdir;
 };
 
-int ref_excluded(struct string_list *, const char *path);
-void clear_ref_exclusion(struct string_list **);
-void add_ref_exclusion(struct string_list **, const char *exclude);
-
-
-#define REV_TREE_SAME		0
-#define REV_TREE_NEW		1	/* Only new files */
-#define REV_TREE_OLD		2	/* Only files removed */
-#define REV_TREE_DIFFERENT	3	/* Mixed changes */
-
-/* revision.c */
-typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
-extern volatile show_early_output_fn_t show_early_output;
-
-struct setup_revision_opt {
-	const char *def;
-	void (*tweak)(struct rev_info *, struct setup_revision_opt *);
-	unsigned int	assume_dashdash:1,
-			allow_exclude_promisor_objects:1;
-	unsigned revarg_opt;
-};
-
-#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
-#define init_revisions(revs, prefix) repo_init_revisions(the_repository, revs, prefix)
-#endif
+/**
+ * Initialize the "struct rev_info" structure with a macro.
+ *
+ * This will not fully initialize a "struct rev_info", the
+ * repo_init_revisions() function needs to be called before
+ * setup_revisions() and any revision walking takes place.
+ *
+ * Use REV_INFO_INIT to make the "struct rev_info" safe for passing to
+ * release_revisions() when it's inconvenient (e.g. due to a "goto
+ * cleanup" pattern) to arrange for repo_init_revisions() to be called
+ * before release_revisions() is called.
+ *
+ * Initializing with this REV_INFO_INIT is redundant to invoking
+ * repo_init_revisions(). If repo_init_revisions() is guaranteed to be
+ * called before release_revisions() the "struct rev_info" can be left
+ * uninitialized.
+ */
+#define REV_INFO_INIT { 0 }
 
 /**
  * Initialize a rev_info structure with default values. The third parameter may
@@ -367,6 +360,9 @@ struct setup_revision_opt {
 void repo_init_revisions(struct repository *r,
 			 struct rev_info *revs,
 			 const char *prefix);
+#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
+#define init_revisions(revs, prefix) repo_init_revisions(the_repository, revs, prefix)
+#endif
 
 /**
  * Parse revision information, filling in the `rev_info` structure, and
@@ -375,9 +371,22 @@ void repo_init_revisions(struct repository *r,
  * head of the argument list. The last parameter is used in case no
  * parameter given by the first two arguments.
  */
+struct setup_revision_opt {
+	const char *def;
+	void (*tweak)(struct rev_info *, struct setup_revision_opt *);
+	unsigned int	assume_dashdash:1,
+			allow_exclude_promisor_objects:1;
+	unsigned revarg_opt;
+};
 int setup_revisions(int argc, const char **argv, struct rev_info *revs,
 		    struct setup_revision_opt *);
 
+/**
+ * Free data allocated in a "struct rev_info" after it's been
+ * initialized with repo_init_revisions() or REV_INFO_INIT.
+ */
+void release_revisions(struct rev_info *revs);
+
 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 			const struct option *options,
 			const char * const usagestr[]);
@@ -419,6 +428,14 @@ void mark_trees_uninteresting_sparse(struct repository *r, struct oidset *trees)
 void show_object_with_name(FILE *, struct object *, const char *);
 
 /**
+ * Helpers to check if a "struct string_list" item matches with
+ * wildmatch().
+ */
+int ref_excluded(struct string_list *, const char *path);
+void clear_ref_exclusion(struct string_list **);
+void add_ref_exclusion(struct string_list **, const char *exclude);
+
+/**
  * This function can be used if you want to add commit objects as revision
  * information. You can use the `UNINTERESTING` object flag to indicate if
  * you want to include or exclude the given commit (and commits reachable
@@ -473,4 +490,10 @@ int rewrite_parents(struct rev_info *revs,
  */
 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit);
 
+/**
+ * Global for the (undocumented) "--early-output" flag for "git log".
+ */
+typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
+extern volatile show_early_output_fn_t show_early_output;
+
 #endif