Merge branch 'mh/tempfile' into pu

Rebuild "lockfile" API on top of a new "tempfile" API.
This needs rerolling, to include "tempfile.h" in "lockfile.h", at
least.

($gmane/271353)

* mh/tempfile:
  credential-cache--daemon: use tempfile module
  credential-cache--daemon: delete socket from main()
  gc: use tempfile module to handle gc.pid file
  lock_repo_for_gc(): compute the path to "gc.pid" only once
  diff: use tempfile module
  setup_temporary_shallow(): use tempfile module
  write_shared_index(): use tempfile module
  register_tempfile(): new function to handle an existing temporary file
  tempfile: add several functions for creating temporary files
  register_tempfile_object(): new function, extracted from create_tempfile()
  commit_lock_file(): use get_locked_file_path()
  lockfile: remove some redundant functions
  tempfile: a new module for handling temporary files
  Move lockfile API documentation to lockfile.h

Makefile

@@ -790,6 +790,7 @@ LIB_OBJS += submodule.o
 LIB_OBJS += submodule-config.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
+LIB_OBJS += tempfile.o
 LIB_OBJS += trace.o
 LIB_OBJS += trailer.o
 LIB_OBJS += transport.o

builtin/add.c

@@ -5,6 +5,7 @@
  */
 #include "cache.h"
 #include "builtin.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "dir.h"
 #include "pathspec.h"

builtin/am.c

@@ -10,6 +10,7 @@
 #include "dir.h"
 #include "run-command.h"
 #include "quote.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "cache-tree.h"
 #include "refs.h"

builtin/apply.c

@@ -7,6 +7,7 @@
  *
  */
 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "cache-tree.h"
 #include "quote.h"

builtin/checkout-index.c

@@ -5,6 +5,7 @@
  *
  */
 #include "builtin.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "quote.h"
 #include "cache-tree.h"

builtin/checkout.c

@@ -1,4 +1,5 @@
 #include "builtin.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "parse-options.h"
 #include "refs.h"

builtin/clone.c

@@ -9,6 +9,7 @@
  */
 
 #include "builtin.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "parse-options.h"
 #include "fetch-pack.h"

builtin/commit.c

@@ -6,6 +6,7 @@
  */
 
 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "cache-tree.h"
 #include "color.h"
@@ -345,7 +346,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 			die(_("unable to write temporary index file"));
 
 		old_index_env = getenv(INDEX_ENVIRONMENT);
-		setenv(INDEX_ENVIRONMENT, index_lock.filename.buf, 1);
+		setenv(INDEX_ENVIRONMENT, index_lock.tempfile.filename.buf, 1);
 
 		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
 			die(_("interactive add failed"));
@@ -356,17 +357,17 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 			unsetenv(INDEX_ENVIRONMENT);
 
 		discard_cache();
-		read_cache_from(index_lock.filename.buf);
+		read_cache_from(index_lock.tempfile.filename.buf);
 		if (update_main_cache_tree(WRITE_TREE_SILENT) == 0) {
-			if (reopen_lock_file(&index_lock) < 0)
+			if (reopen_tempfile(&index_lock.tempfile) < 0)
 				die(_("unable to write index file"));
 			if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
 				die(_("unable to write temporary index file"));
 		} else
 			warning(_("Failed to update main cache tree"));
 
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return index_lock.tempfile.filename.buf;
 	}
 
 	/*
@@ -389,7 +390,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 		if (write_locked_index(&the_index, &index_lock, CLOSE_LOCK))
 			die(_("unable to write index file"));
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return index_lock.tempfile.filename.buf;
 	}
 
 	/*
@@ -477,9 +478,9 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 		die(_("unable to write temporary index file"));
 
 	discard_cache();
-	read_cache_from(false_lock.filename.buf);
+	read_cache_from(false_lock.tempfile.filename.buf);
 
-	return false_lock.filename.buf;
+	return false_lock.tempfile.filename.buf;
 }
 
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,

builtin/describe.c

@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "commit.h"
 #include "tag.h"

builtin/diff.c

@@ -4,6 +4,7 @@
  * Copyright (c) 2006 Junio C Hamano
  */
 #include "cache.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "color.h"
 #include "commit.h"