write_file(): drop "fatal" parameter

All callers except three passed 1 for the "fatal" parameter to ask
this function to die upon error, but to a casual reader of the code,
it was not all obvious what that 1 meant.  Instead, split the
function into two based on a common write_file_v() that takes the
flag, introduce write_file_gently() as a new way to attempt creating
a file without dying on error, and make three callers to call it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/am.c

@@ -205,13 +205,13 @@ static int write_state_text(const struct am_state *state,
 		fmt = "%s\n";
 	else
 		fmt = "%s";
-	return write_file(am_path(state, name), 1, fmt, string);
+	return write_file(am_path(state, name), fmt, string);
 }
 
 static int write_state_count(const struct am_state *state,
 			     const char *name, int value)
 {
-	return write_file(am_path(state, name), 1, "%d\n", value);
+	return write_file(am_path(state, name), "%d\n", value);
 }
 
 static int write_state_bool(const struct am_state *state,

builtin/branch.c

@@ -776,7 +776,7 @@ static int edit_branch_description(const char *branch_name)
 		    "  %s\n"
 		    "Lines starting with '%c' will be stripped.\n",
 		    branch_name, comment_line_char);
-	if (write_file(git_path(edit_description), 0, "%s", buf.buf)) {
+	if (write_file_gently(git_path(edit_description), "%s", buf.buf)) {
 		strbuf_release(&buf);
 		return error(_("could not write branch description template: %s"),
 			     strerror(errno));

builtin/init-db.c

@@ -378,7 +378,7 @@ static void separate_git_dir(const char *git_dir)
 			die_errno(_("unable to move %s to %s"), src, git_dir);
 	}
 
-	write_file(git_link, 1, "gitdir: %s\n", git_dir);
+	write_file(git_link, "gitdir: %s\n", git_dir);
 }
 
 int init_db(const char *template_dir, unsigned int flags)

builtin/worktree.c

@@ -213,7 +213,7 @@ static int add_worktree(const char *path, const char **child_argv)
 	 * after the preparation is over.
 	 */
 	strbuf_addf(&sb, "%s/locked", sb_repo.buf);
-	write_file(sb.buf, 1, "initializing\n");
+	write_file(sb.buf, "initializing\n");
 
 	strbuf_addf(&sb_git, "%s/.git", path);
 	if (safe_create_leading_directories_const(sb_git.buf))
@@ -223,8 +223,8 @@ static int add_worktree(const char *path, const char **child_argv)
 
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
-	write_file(sb.buf, 1, "%s\n", real_path(sb_git.buf));
-	write_file(sb_git.buf, 1, "gitdir: %s/worktrees/%s\n",
+	write_file(sb.buf, "%s\n", real_path(sb_git.buf));
+	write_file(sb_git.buf, "gitdir: %s/worktrees/%s\n",
 		   real_path(get_git_common_dir()), name);
 	/*
 	 * This is to keep resolve_ref() happy. We need a valid HEAD
@@ -241,10 +241,10 @@ static int add_worktree(const char *path, const char **child_argv)
 		die(_("unable to resolve HEAD"));
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
-	write_file(sb.buf, 1, "%s\n", sha1_to_hex(rev));
+	write_file(sb.buf, "%s\n", sha1_to_hex(rev));
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
-	write_file(sb.buf, 1, "../..\n");
+	write_file(sb.buf, "../..\n");
 
 	fprintf_ln(stderr, _("Enter %s (identifier %s)"), path, name);