unpack_trees_options: free messages when done

The strings allocated in `setup_unpack_trees_porcelain()` are never
freed. Provide a function `clear_unpack_trees_porcelain()` to do so and
call it where we use `setup_unpack_trees_porcelain()`. The only
non-trivial user is `unpack_trees_start()`, where we should place the
new call in `unpack_trees_finish()`.

We keep the string pointers in an array, mixing pointers to static
memory and memory that we allocate on the heap. We also keep several
copies of the individual pointers. So we need to make sure that we do
not free what we must not free and that we do not double-free. Let a
separate argv_array take ownership of all the strings we create so that
we can easily free them.

Zero the whole array of string pointers to make sure that we do not
leave any dangling pointers.

Note that we only take responsibility for the memory allocated in
`setup_unpack_trees_porcelain()` and not any other members of the
`struct unpack_trees_options`.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index b49b5820718335ba6a70b70ef339ece7157281cc..5cebe170fc1937c4eafd912f7d09860f5b2ebff2 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -526,6 +526,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
                init_tree_desc(&trees[1], tree->buffer, tree->size);
 
                ret = unpack_trees(2, trees, &topts);
+               clear_unpack_trees_porcelain(&topts);
                if (ret == -1) {
                        /*
                         * Unpack couldn't do a trivial merge; either

diff --git a/merge-recursive.c b/merge-recursive.c
index ddb0fa73698122542e727befa7fbedf47b9226bf..338f63a952b1f4a7a736ff5506362304760877b2 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -382,6 +382,7 @@ static int unpack_trees_start(struct merge_options *o,
 static void unpack_trees_finish(struct merge_options *o)
 {
        discard_index(&o->orig_index);
+       clear_unpack_trees_porcelain(&o->unpack_opts);
 }
 
 struct tree *write_tree_from_memory(struct merge_options *o)

diff --git a/merge.c b/merge.c
index f123658e582fc1f142b25bb8c71b5dcbe84fe3aa..b433291d0c376ea3ba0a1c56b465cc1b91da4ddf 100644 (file)
--- a/merge.c
+++ b/merge.c
@@ -130,8 +130,11 @@ int checkout_fast_forward(const struct object_id *head,
 
        if (unpack_trees(nr_trees, t, &opts)) {
                rollback_lock_file(&lock_file);
+               clear_unpack_trees_porcelain(&opts);
                return -1;
        }
+       clear_unpack_trees_porcelain(&opts);
+
        if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
                return error(_("unable to write new index file"));
        return 0;

diff --git a/unpack-trees.c b/unpack-trees.c
index 79fd97074ec238714634de1c9e6144accdc710f3..73a6dc1701fbc969a65efd2afb6eeab7130fa228 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1,5 +1,6 @@
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "argv-array.h"
 #include "repository.h"
 #include "config.h"
 #include "dir.h"
@@ -103,6 +104,8 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
        const char **msgs = opts->msgs;
        const char *msg;
 
+       argv_array_init(&opts->msgs_to_free);
+
        if (!strcmp(cmd, "checkout"))
                msg = advice_commit_before_merge
                      ? _("Your local changes to the following files would be overwritten by checkout:\n%%s"
@@ -119,7 +122,7 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                          "Please commit your changes or stash them before you %s.")
                      : _("Your local changes to the following files would be overwritten by %s:\n%%s");
        msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
-               xstrfmt(msg, cmd, cmd);
+               argv_array_pushf(&opts->msgs_to_free, msg, cmd, cmd);
 
        msgs[ERROR_NOT_UPTODATE_DIR] =
                _("Updating the following directories would lose untracked files in them:\n%s");
@@ -139,7 +142,8 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                      ? _("The following untracked working tree files would be removed by %s:\n%%s"
                          "Please move or remove them before you %s.")
                      : _("The following untracked working tree files would be removed by %s:\n%%s");
-       msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = xstrfmt(msg, cmd, cmd);
+       msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] =
+               argv_array_pushf(&opts->msgs_to_free, msg, cmd, cmd);
 
        if (!strcmp(cmd, "checkout"))
                msg = advice_commit_before_merge
@@ -156,7 +160,8 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                      ? _("The following untracked working tree files would be overwritten by %s:\n%%s"
                          "Please move or remove them before you %s.")
                      : _("The following untracked working tree files would be overwritten by %s:\n%%s");
-       msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = xstrfmt(msg, cmd, cmd);
+       msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] =
+               argv_array_pushf(&opts->msgs_to_free, msg, cmd, cmd);
 
        /*
         * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
@@ -179,6 +184,12 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                opts->unpack_rejects[i].strdup_strings = 1;
 }
 
+void clear_unpack_trees_porcelain(struct unpack_trees_options *opts)
+{
+       argv_array_clear(&opts->msgs_to_free);
+       memset(opts->msgs, 0, sizeof(opts->msgs));
+}
+
 static int do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
                         unsigned int set, unsigned int clear)
 {

diff --git a/unpack-trees.h b/unpack-trees.h
index 41178ada94a4b7c5222cab7dd17d9eeb7a1956e4..c2b434c60648fb0e287c100a32d9346a765ab74f 100644 (file)
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -2,7 +2,7 @@
 #define UNPACK_TREES_H
 
 #include "tree-walk.h"
-#include "string-list.h"
+#include "argv-array.h"
 
 #define MAX_UNPACK_TREES 8
 
@@ -33,6 +33,11 @@ enum unpack_trees_error_types {
 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                                  const char *cmd);
 
+/*
+ * Frees resources allocated by setup_unpack_trees_porcelain().
+ */
+void clear_unpack_trees_porcelain(struct unpack_trees_options *opts);
+
 struct unpack_trees_options {
        unsigned int reset,
                     merge,
@@ -57,6 +62,7 @@ struct unpack_trees_options {
        struct pathspec *pathspec;
        merge_fn_t fn;
        const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
+       struct argv_array msgs_to_free;
        /*
         * Store error messages in an array, each case
         * corresponding to a error message type