[PATCH 1/2] launch_editor(): Heed GIT_EDITOR and core.editor settings

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

In the commit 'Add GIT_EDITOR environment and core.editor
configuration variables', this was done for the shell scripts.
Port it over to builtin-tag's version of launch_editor(), which
is just about to be refactored into editor.c.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 builtin-tag.c |    6 +++++-
 cache.h       |    2 ++
 config.c      |    5 +++++
 environment.c |    1 +
 4 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/builtin-tag.c b/builtin-tag.c
index 507f510..cf36def 100644
--- a/builtin-tag.c
+++ b/builtin-tag.c
@@ -24,7 +24,11 @@ static void launch_editor(const char *path, char **buffer, unsigned long *len)
 	const char *args[3];
 	int fd;
 
-	editor = getenv("VISUAL");
+	editor = getenv("GIT_EDITOR");
+	if (!editor && editor_program)
+		editor = editor_program;
+	if (!editor)
+		editor = getenv("VISUAL");
 	if (!editor)
 		editor = getenv("EDITOR");
 
diff --git a/cache.h b/cache.h
index 1b88d75..0c12ce8 100644
--- a/cache.h
+++ b/cache.h
@@ -564,6 +564,8 @@ extern char *pager_program;
 extern int pager_in_use;
 extern int pager_use_color;
 
+extern char *editor_program;
+
 /* base85 */
 int decode_85(char *dst, const char *line, int linelen);
 void encode_85(char *buf, const unsigned char *data, int bytes);
diff --git a/config.c b/config.c
index bdbfdec..9d8e9dc 100644
--- a/config.c
+++ b/config.c
@@ -431,6 +431,11 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.editor")) {
+		editor_program = xstrdup(value);
+		return 0;
+	}
+
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
 }
diff --git a/environment.c b/environment.c
index 04d06b6..2e9d505 100644
--- a/environment.c
+++ b/environment.c
@@ -33,6 +33,7 @@ size_t delta_base_cache_limit = 16 * 1024 * 1024;
 char *pager_program;
 int pager_in_use;
 int pager_use_color = 1;
+char *editor_program;
 int auto_crlf = 0;	/* 1: both ways, -1: only when adding git objects */
 int show_commit_annotations;
 
-- 
1.5.3.rc1.16.g9d6f-dirty