Merge branch 'jk/alt-odb-cleanup'

Codepaths involved in interacting alternate object store have
been cleaned up.

* jk/alt-odb-cleanup:
  alternates: use fspathcmp to detect duplicates
  sha1_file: always allow relative paths to alternates
  count-objects: report alternates via verbose mode
  fill_sha1_file: write into a strbuf
  alternates: store scratch buffer as strbuf
  fill_sha1_file: write "boring" characters
  alternates: use a separate scratch space
  alternates: encapsulate alt->base munging
  alternates: provide helper for allocating alternate
  alternates: provide helper for adding to alternates list
  link_alt_odb_entry: refactor string handling
  link_alt_odb_entry: handle normalize_path errors
  t5613: clarify "too deep" recursion tests
  t5613: do not chdir in main process
  t5613: whitespace/style cleanups
  t5613: use test_must_fail
  t5613: drop test_valid_repo function
  t5613: drop reachable_via function

Author: gitster

Documentation/git-count-objects.txt

@@ -38,6 +38,11 @@ objects nor valid packs
 +
 size-garbage: disk space consumed by garbage files, in KiB (unless -H is
 specified)
++
+alternate: absolute path of alternate object databases; may appear
+multiple times, one line per path. Note that if the path contains
+non-printable characters, it may be surrounded by double-quotes and
+contain C-style backslashed escape sequences.
 
 -H::
 --human-readable::

builtin/count-objects.c

@@ -8,6 +8,7 @@
 #include "dir.h"
 #include "builtin.h"
 #include "parse-options.h"
+#include "quote.h"
 
 static unsigned long garbage;
 static off_t size_garbage;
@@ -73,6 +74,14 @@ static int count_cruft(const char *basename, const char *path, void *data)
 	return 0;
 }
 
+static int print_alternate(struct alternate_object_database *alt, void *data)
+{
+	printf("alternate: ");
+	quote_c_style(alt->path, NULL, stdout, 0);
+	putchar('\n');
+	return 0;
+}
+
 static char const * const count_objects_usage[] = {
 	N_("git count-objects [-v] [-H | --human-readable]"),
 	NULL
@@ -88,6 +97,8 @@ int cmd_count_objects(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
+	git_config(git_default_config, NULL);
+
 	argc = parse_options(argc, argv, prefix, opts, count_objects_usage, 0);
 	/* we do not take arguments other than flags for now */
 	if (argc)
@@ -140,6 +151,7 @@ int cmd_count_objects(int argc, const char **argv, const char *prefix)
 		printf("prune-packable: %lu\n", packed_loose);
 		printf("garbage: %lu\n", garbage);
 		printf("size-garbage: %s\n", garbage_buf.buf);
+		foreach_alt_odb(print_alternate, NULL);
 		strbuf_release(&loose_buf);
 		strbuf_release(&pack_buf);
 		strbuf_release(&garbage_buf);

builtin/fsck.c

@@ -644,14 +644,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 		fsck_object_dir(get_object_directory());
 
 		prepare_alt_odb();
-		for (alt = alt_odb_list; alt; alt = alt->next) {
-			/* directory name, minus trailing slash */
-			size_t namelen = alt->name - alt->base - 1;
-			struct strbuf name = STRBUF_INIT;
-			strbuf_add(&name, alt->base, namelen);
-			fsck_object_dir(name.buf);
-			strbuf_release(&name);
-		}
+		for (alt = alt_odb_list; alt; alt = alt->next)
+			fsck_object_dir(alt->path);
 	}
 
 	if (check_full) {

builtin/submodule--helper.c

@@ -492,20 +492,16 @@ static int add_possible_reference_from_superproject(
 {
 	struct submodule_alternate_setup *sas = sas_cb;
 
-	/* directory name, minus trailing slash */
-	size_t namelen = alt->name - alt->base - 1;
-	struct strbuf name = STRBUF_INIT;
-	strbuf_add(&name, alt->base, namelen);
-
 	/*
 	 * If the alternate object store is another repository, try the
 	 * standard layout with .git/modules/<name>/objects
 	 */
-	if (ends_with(name.buf, ".git/objects")) {
+	if (ends_with(alt->path, ".git/objects")) {
 		char *sm_alternate;
 		struct strbuf sb = STRBUF_INIT;
 		struct strbuf err = STRBUF_INIT;
-		strbuf_add(&sb, name.buf, name.len - strlen("objects"));
+		strbuf_add(&sb, alt->path, strlen(alt->path) - strlen("objects"));
+
 		/*
 		 * We need to end the new path with '/' to mark it as a dir,
 		 * otherwise a submodule name containing '/' will be broken
@@ -533,7 +529,6 @@ static int add_possible_reference_from_superproject(
 		strbuf_release(&sb);
 	}
 
-	strbuf_release(&name);
 	return 0;
 }
 

cache.h

@@ -1390,16 +1390,46 @@ extern void remove_scheduled_dirs(void);
 
 extern struct alternate_object_database {
 	struct alternate_object_database *next;
-	char *name;
-	char base[FLEX_ARRAY]; /* more */
+
+	/* see alt_scratch_buf() */
+	struct strbuf scratch;
+	size_t base_len;
+
+	char path[FLEX_ARRAY];
 } *alt_odb_list;
 extern void prepare_alt_odb(void);
 extern void read_info_alternates(const char * relative_base, int depth);
 extern char *compute_alternate_path(const char *path, struct strbuf *err);
-extern void add_to_alternates_file(const char *reference);
 typedef int alt_odb_fn(struct alternate_object_database *, void *);
 extern int foreach_alt_odb(alt_odb_fn, void*);
 
+/*
+ * Allocate a "struct alternate_object_database" but do _not_ actually
+ * add it to the list of alternates.
+ */
+struct alternate_object_database *alloc_alt_odb(const char *dir);
+
+/*
+ * Add the directory to the on-disk alternates file; the new entry will also
+ * take effect in the current process.
+ */
+extern void add_to_alternates_file(const char *dir);
+
+/*
+ * Add the directory to the in-memory list of alternates (along with any
+ * recursive alternates it points to), but do not modify the on-disk alternates
+ * file.
+ */
+extern void add_to_alternates_memory(const char *dir);
+
+/*
+ * Returns a scratch strbuf pre-filled with the alternate object directory,
+ * including a trailing slash, which can be used to access paths in the
+ * alternate. Always use this over direct access to alt->scratch, as it
+ * cleans up any previous use of the scratch buffer.
+ */
+extern struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
+
 struct pack_window {
 	struct pack_window *next;
 	unsigned char *base;