grass.app: Move ISIS integration to the library (OSGeo#4169)

Path setup for ISIS was lost in GIS variable setup. This moves it to the library, where other paths and integrations are initialized.

The variables are left as is, without further testing.

lib/init/grass.py

@@ -1073,20 +1073,6 @@ def load_env(grass_env_file):
         # create a new environment variable
         os.environ[k] = v
 
-    # Allow for mixed ISIS-GRASS Environment
-    if os.getenv("ISISROOT"):
-        isis = os.getenv("ISISROOT")
-        os.environ["ISIS_LIB"] = isis + os.sep + "lib"
-        os.environ["ISIS_3RDPARTY"] = isis + os.sep + "3rdParty" + os.sep + "lib"
-        os.environ["QT_PLUGIN_PATH"] = isis + os.sep + "3rdParty" + os.sep + "plugins"
-        # os.environ['ISIS3DATA'] = isis + "$ISIS3DATA"
-        libpath = os.getenv("LD_LIBRARY_PATH", "")
-        isislibpath = os.getenv("ISIS_LIB")
-        isis3rdparty = os.getenv("ISIS_3RDPARTY")
-        os.environ["LD_LIBRARY_PATH"] = (
-            libpath + os.pathsep + isislibpath + os.pathsep + isis3rdparty
-        )
-
 
 def install_notranslation():
     # If locale is not supported, _ function might be missing

python/grass/app/runtime.py

@@ -129,6 +129,7 @@ def set_paths(install_path, grass_config_dir, ld_library_path_variable_name):
     # retrieving second time, but now it is always set
     addon_base = os.getenv("GRASS_ADDON_BASE")
     set_man_path(install_path=install_path, addon_base=addon_base, env=os.environ)
+    set_isis()
 
 
 def set_man_path(install_path, addon_base, env):
@@ -274,6 +275,25 @@ def set_browser(install_path):
     os.environ["GRASS_HTML_BROWSER"] = browser
 
 
+def set_isis():
+    """Enable a mixed ISIS-GRASS environment
+
+    ISIS is Integrated Software for Imagers and Spectrometers by USGS.
+    """
+    if os.getenv("ISISROOT"):
+        isis = os.getenv("ISISROOT")
+        os.environ["ISIS_LIB"] = isis + os.sep + "lib"
+        os.environ["ISIS_3RDPARTY"] = isis + os.sep + "3rdParty" + os.sep + "lib"
+        os.environ["QT_PLUGIN_PATH"] = isis + os.sep + "3rdParty" + os.sep + "plugins"
+        # os.environ['ISIS3DATA'] = isis + "$ISIS3DATA"
+        libpath = os.getenv("LD_LIBRARY_PATH", "")
+        isislibpath = os.getenv("ISIS_LIB")
+        isis3rdparty = os.getenv("ISIS_3RDPARTY")
+        os.environ["LD_LIBRARY_PATH"] = (
+            libpath + os.pathsep + isislibpath + os.pathsep + isis3rdparty
+        )
+
+
 def ensure_home():
     """Set HOME if not set on MS Windows"""
     if WINDOWS and not os.getenv("HOME"):