Merge branch 'mh/tempfile'

The "lockfile" API has been rebuilt on top of a new "tempfile" API.

* 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
  prepare_tempfile_object(): new function, extracted from create_tempfile()
  tempfile: a new module for handling temporary files
  commit_lock_file(): use get_locked_file_path()
  lockfile: add accessor get_lock_file_path()
  lockfile: add accessors get_lock_file_fd() and get_lock_file_fp()
  create_bundle(): duplicate file descriptor to avoid closing it twice
  lockfile: move documentation to lockfile.h and lockfile.c

Author: gitster

Documentation/technical/api-lockfile.txt

@@ -786,6 +786,7 @@ LIB_OBJS += string-list.o
 LIB_OBJS += submodule.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

Makefile

@@ -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/am.c

@@ -324,6 +324,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 	struct string_list partial;
 	struct pathspec pathspec;
 	int refresh_flags = REFRESH_QUIET;
+	const char *ret;
 
 	if (is_status)
 		refresh_flags |= REFRESH_UNMERGED;
@@ -344,7 +345,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 			die(_("unable to create temporary index"));
 
 		old_index_env = getenv(INDEX_ENVIRONMENT);
-		setenv(INDEX_ENVIRONMENT, index_lock.filename.buf, 1);
+		setenv(INDEX_ENVIRONMENT, get_lock_file_path(&index_lock), 1);
 
 		if (interactive_add(argc, argv, prefix, patch_interactive) != 0)
 			die(_("interactive add failed"));
@@ -355,7 +356,7 @@ 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(get_lock_file_path(&index_lock));
 		if (update_main_cache_tree(WRITE_TREE_SILENT) == 0) {
 			if (reopen_lock_file(&index_lock) < 0)
 				die(_("unable to write index file"));
@@ -365,7 +366,7 @@ static const char *prepare_index(int argc, const char **argv, const char *prefix
 			warning(_("Failed to update main cache tree"));
 
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return get_lock_file_path(&index_lock);
 	}
 
 	/*
@@ -388,7 +389,7 @@ 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 new_index file"));
 		commit_style = COMMIT_NORMAL;
-		return index_lock.filename.buf;
+		return get_lock_file_path(&index_lock);
 	}
 
 	/*
@@ -475,9 +476,9 @@ 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);
-
-	return false_lock.filename.buf;
+	ret = get_lock_file_path(&false_lock);
+	read_cache_from(ret);
+	return ret;
 }
 
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,

builtin/commit.c

@@ -11,6 +11,7 @@
  */
 
 #include "builtin.h"
+#include "tempfile.h"
 #include "lockfile.h"
 #include "parse-options.h"
 #include "run-command.h"
@@ -42,20 +43,7 @@ static struct argv_array prune = ARGV_ARRAY_INIT;
 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
 static struct argv_array rerere = ARGV_ARRAY_INIT;
 
-static char *pidfile;
-
-static void remove_pidfile(void)
-{
-	if (pidfile)
-		unlink(pidfile);
-}
-
-static void remove_pidfile_on_signal(int signo)
-{
-	remove_pidfile();
-	sigchain_pop(signo);
-	raise(signo);
-}
+static struct tempfile pidfile;
 
 static void git_config_date_string(const char *key, const char **output)
 {
@@ -199,20 +187,22 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
 	uintmax_t pid;
 	FILE *fp;
 	int fd;
+	char *pidfile_path;
 
-	if (pidfile)
+	if (is_tempfile_active(&pidfile))
 		/* already locked */
 		return NULL;
 
 	if (gethostname(my_host, sizeof(my_host)))
 		strcpy(my_host, "unknown");
 
-	fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
+	pidfile_path = git_pathdup("gc.pid");
+	fd = hold_lock_file_for_update(&lock, pidfile_path,
 				       LOCK_DIE_ON_ERROR);
 	if (!force) {
 		static char locking_host[128];
 		int should_exit;
-		fp = fopen(git_path("gc.pid"), "r");
+		fp = fopen(pidfile_path, "r");
 		memset(locking_host, 0, sizeof(locking_host));
 		should_exit =
 			fp != NULL &&
@@ -236,6 +226,7 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
 			if (fd >= 0)
 				rollback_lock_file(&lock);
 			*ret_pid = pid;
+			free(pidfile_path);
 			return locking_host;
 		}
 	}
@@ -245,11 +236,8 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
 	write_in_full(fd, sb.buf, sb.len);
 	strbuf_release(&sb);
 	commit_lock_file(&lock);
-
-	pidfile = git_pathdup("gc.pid");
-	sigchain_push_common(remove_pidfile_on_signal);
-	atexit(remove_pidfile);
-
+	register_tempfile(&pidfile, pidfile_path);
+	free(pidfile_path);
 	return NULL;
 }
 

builtin/gc.c

@@ -15,6 +15,7 @@
 #include "dir.h"
 #include "refs.h"
 #include "revision.h"
+#include "tempfile.h"
 #include "lockfile.h"
 
 enum rebase_type {