Merge branch 'kf/askpass-config'

* kf/askpass-config:
  Extend documentation of core.askpass and GIT_ASKPASS.
  Allow core.askpass to override SSH_ASKPASS.
  Add a new option 'core.askpass'.

Author: gitster

Documentation/config.txt

@@ -450,6 +450,15 @@ core.excludesfile::
 	to the value of `$HOME` and "{tilde}user/" to the specified user's
 	home directory.  See linkgit:gitignore[5].
 
+core.askpass::
+	Some commands (e.g. svn and http interfaces) that interactively
+	ask for a password can be told to use an external program given
+	via the value of this variable. Can be overridden by the 'GIT_ASKPASS'
+	environment variable. If not set, fall back to the value of the
+	'SSH_ASKPASS' environment variable or, failing that, a simple password
+	prompt. The external program shall be given a suitable prompt as
+	command line argument and write the password on its STDOUT.
+
 core.editor::
 	Commands such as `commit` and `tag` that lets you edit
 	messages by launching an editor uses the value of this

Documentation/git.txt

@@ -639,6 +639,13 @@ Usually it is easier to configure any desired options through your
 personal `.ssh/config` file.  Please consult your ssh documentation
 for further details.
 
+'GIT_ASKPASS'::
+	If this environment variable is set, then git commands which need to
+	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
+	will call this program with a suitable prompt as command line argument
+	and read the password from its STDOUT. See also the 'core.askpass'
+	option in linkgit:git-config[1].
+
 'GIT_FLUSH'::
 	If this environment variable is set to "1", then commands such
 	as 'git blame' (in incremental mode), 'git rev-list', 'git log',

cache.h

@@ -1035,6 +1035,7 @@ extern int pager_in_use(void);
 extern int pager_use_color;
 
 extern const char *editor_program;
+extern const char *askpass_program;
 extern const char *excludes_file;
 
 /* base85 */

config.c

@@ -605,6 +605,9 @@ static int git_default_core_config(const char *var, const char *value)
 	if (!strcmp(var, "core.editor"))
 		return git_config_string(&editor_program, var, value);
 
+	if (!strcmp(var, "core.askpass"))
+		return git_config_string(&askpass_program, var, value);
+
 	if (!strcmp(var, "core.excludesfile"))
 		return git_config_pathname(&excludes_file, var, value);
 

connect.c

@@ -621,13 +621,16 @@ int finish_connect(struct child_process *conn)
 
 char *git_getpass(const char *prompt)
 {
-	char *askpass;
+	const char *askpass;
 	struct child_process pass;
 	const char *args[3];
 	static struct strbuf buffer = STRBUF_INIT;
 
 	askpass = getenv("GIT_ASKPASS");
-
+	if (!askpass)
+		askpass = askpass_program;
+	if (!askpass)
+		askpass = getenv("SSH_ASKPASS");
 	if (!askpass || !(*askpass))
 		return getpass(prompt);
 

environment.c

@@ -37,6 +37,7 @@ size_t delta_base_cache_limit = 16 * 1024 * 1024;
 const char *pager_program;
 int pager_use_color = 1;
 const char *editor_program;
+const char *askpass_program;
 const char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
 int read_replace_refs = 1;

git.c

@@ -56,9 +56,6 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 {
 	int handled = 0;
 
-	if (!getenv("GIT_ASKPASS") && getenv("SSH_ASKPASS"))
-		setenv("GIT_ASKPASS", getenv("SSH_ASKPASS"), 1);
-
 	while (*argc > 0) {
 		const char *cmd = (*argv)[0];
 		if (cmd[0] != '-')