1 files changed, 34 insertions, 21 deletions

diff --git a/builtin/difftool.c b/builtin/difftool.c
index dbbfb19f19..a1794b7eed 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -11,19 +11,26 @@
  *
  * Copyright (C) 2016 Johannes Schindelin
  */
-#define USE_THE_INDEX_VARIABLE
-#include "cache.h"
-#include "config.h"
+
 #include "builtin.h"
+#include "abspath.h"
+#include "config.h"
+#include "copy.h"
 #include "run-command.h"
-#include "exec-cmd.h"
+#include "environment.h"
+#include "gettext.h"
+#include "hex.h"
 #include "parse-options.h"
+#include "read-cache-ll.h"
+#include "sparse-index.h"
 #include "strvec.h"
 #include "strbuf.h"
 #include "lockfile.h"
-#include "object-store.h"
+#include "object-file.h"
+#include "object-store-ll.h"
 #include "dir.h"
 #include "entry.h"
+#include "setup.h"
 
 static int trust_exit_code;
 
@@ -32,14 +39,15 @@ static const char *const builtin_difftool_usage[] = {
 	NULL
 };
 
-static int difftool_config(const char *var, const char *value, void *cb)
+static int difftool_config(const char *var, const char *value,
+			   const struct config_context *ctx, void *cb)
 {
 	if (!strcmp(var, "difftool.trustexitcode")) {
 		trust_exit_code = git_config_bool(var, value);
 		return 0;
 	}
 
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, ctx, cb);
 }
 
 static int print_tool_help(void)
@@ -109,7 +117,7 @@ static int use_wt_file(const char *workdir, const char *name,
 		int fd = open(buf.buf, O_RDONLY);
 
 		if (fd >= 0 &&
-		    !index_fd(&the_index, &wt_oid, fd, &st, OBJ_BLOB, name, 0)) {
+		    !index_fd(the_repository->index, &wt_oid, fd, &st, OBJ_BLOB, name, 0)) {
 			if (is_null_oid(oid)) {
 				oidcpy(oid, &wt_oid);
 				use = 1;
@@ -295,7 +303,8 @@ static char *get_symlink(const struct object_id *oid, const char *path)
 	} else {
 		enum object_type type;
 		unsigned long size;
-		data = read_object_file(oid, &type, &size);
+		data = repo_read_object_file(the_repository, oid, &type,
+					     &size);
 		if (!data)
 			die(_("could not read object %s for symlink %s"),
 				oid_to_hex(oid), path);
@@ -665,26 +674,22 @@ finish:
 static int run_file_diff(int prompt, const char *prefix,
 			 struct child_process *child)
 {
-	const char *env[] = {
-		"GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL,
-		NULL
-	};
-
+	strvec_push(&child->env, "GIT_PAGER=");
+	strvec_push(&child->env, "GIT_EXTERNAL_DIFF=git-difftool--helper");
 	if (prompt > 0)
-		env[2] = "GIT_DIFFTOOL_PROMPT=true";
+		strvec_push(&child->env, "GIT_DIFFTOOL_PROMPT=true");
 	else if (!prompt)
-		env[2] = "GIT_DIFFTOOL_NO_PROMPT=true";
+		strvec_push(&child->env, "GIT_DIFFTOOL_NO_PROMPT=true");
 
 	child->git_cmd = 1;
 	child->dir = prefix;
-	strvec_pushv(&child->env, env);
 
 	return run_command(child);
 }
 
 int cmd_difftool(int argc, const char **argv, const char *prefix)
 {
-	int use_gui_tool = 0, dir_diff = 0, prompt = -1, symlinks = 0,
+	int use_gui_tool = -1, dir_diff = 0, prompt = -1, symlinks = 0,
 	    tool_help = 0, no_index = 0;
 	static char *difftool_cmd = NULL, *extcmd = NULL;
 	struct option builtin_difftool_options[] = {
@@ -734,13 +739,21 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
 	} else if (dir_diff)
 		die(_("options '%s' and '%s' cannot be used together"), "--dir-diff", "--no-index");
 
-	die_for_incompatible_opt3(use_gui_tool, "--gui",
+	die_for_incompatible_opt3(use_gui_tool == 1, "--gui",
 				  !!difftool_cmd, "--tool",
 				  !!extcmd, "--extcmd");
 
-	if (use_gui_tool)
+	/*
+	 * Explicitly specified GUI option is forwarded to git-mergetool--lib.sh;
+	 * empty or unset means "use the difftool.guiDefault config or default to
+	 * false".
+	 */
+	if (use_gui_tool == 1)
 		setenv("GIT_MERGETOOL_GUI", "true", 1);
-	else if (difftool_cmd) {
+	else if (use_gui_tool == 0)
+		setenv("GIT_MERGETOOL_GUI", "false", 1);
+
+	if (difftool_cmd) {
 		if (*difftool_cmd)
 			setenv("GIT_DIFF_TOOL", difftool_cmd, 1);
 		else