BLF translation: fix BLF_lang_get(), add UI-agnostic BLF_translate/_do helpers.

BLF_lang_get() shall return 'default' Blender locale (en_US) when translations
are completely disabled!

Also, add BLF_translate() and BLF_translate_do() to allow translating some strings
outside of label/tip context, but still only when i18n global flag is enabled.

3 files changed, 34 insertions, 5 deletions

diff --git a/source/blender/blenfont/BLF_translation.h b/source/blender/blenfont/BLF_translation.h
index 49bfdbfe877..c9b0c253ed4 100644
--- a/source/blender/blenfont/BLF_translation.h
+++ b/source/blender/blenfont/BLF_translation.h
@@ -79,9 +79,11 @@ bool BLF_is_default_context(const char *msgctxt);
 const char *BLF_pgettext(const char *msgctxt, const char *msgid);
 
 /* translation */
+bool BLF_translate(void);
 bool BLF_translate_iface(void);
 bool BLF_translate_tooltips(void);
 bool BLF_translate_new_dataname(void);
+const char *BLF_translate_do(const char *msgctxt, const char *msgid);
 const char *BLF_translate_do_iface(const char *msgctxt, const char *msgid);
 const char *BLF_translate_do_tooltip(const char *msgctxt, const char *msgid);
 const char *BLF_translate_do_new_dataname(const char *msgctxt, const char *msgid);
diff --git a/source/blender/blenfont/intern/blf_lang.c b/source/blender/blenfont/intern/blf_lang.c
index 99e1aa5d3e3..4683081a1ed 100644
--- a/source/blender/blenfont/intern/blf_lang.c
+++ b/source/blender/blenfont/intern/blf_lang.c
@@ -284,12 +284,15 @@ void BLF_lang_set(const char *str)
 const char *BLF_lang_get(void)
 {
 #ifdef WITH_INTERNATIONAL
-	const char *locale = LOCALE(ULANGUAGE);
-	if (locale[0] == '\0') {
-		/* Default locale, we have to find which one we are actually using! */
-		locale = bl_locale_get();
+	if (BLF_translate()) {
+		const char *locale = LOCALE(ULANGUAGE);
+		if (locale[0] == '\0') {
+			/* Default locale, we have to find which one we are actually using! */
+			locale = bl_locale_get();
+		}
+		return locale;
 	}
-	return locale;
+	return "en_US";  /* Kind of default locale in Blender when no translation enabled. */
 #else
 	return "";
 #endif
diff --git a/source/blender/blenfont/intern/blf_translation.c b/source/blender/blenfont/intern/blf_translation.c
index 2a4a152f0eb..25464864657 100644
--- a/source/blender/blenfont/intern/blf_translation.c
+++ b/source/blender/blenfont/intern/blf_translation.c
@@ -164,6 +164,15 @@ const char *BLF_pgettext(const char *msgctxt, const char *msgid)
 #endif
 }
 
+bool BLF_translate(void)
+{
+#ifdef WITH_INTERNATIONAL
+	return (U.transopts & USER_DOTRANSLATE) != 0;
+#else
+	return false;
+#endif
+}
+
 bool BLF_translate_iface(void)
 {
 #ifdef WITH_INTERNATIONAL
@@ -191,6 +200,21 @@ bool BLF_translate_new_dataname(void)
 #endif
 }
 
+const char *BLF_translate_do(const char *msgctxt, const char *msgid)
+{
+#ifdef WITH_INTERNATIONAL
+	if (BLF_translate()) {
+		return BLF_pgettext(msgctxt, msgid);
+	}
+	else {
+		return msgid;
+	}
+#else
+	(void)msgctxt;
+	return msgid;
+#endif
+}
+
 const char *BLF_translate_do_iface(const char *msgctxt, const char *msgid)
 {
 #ifdef WITH_INTERNATIONAL