[meld] Merge branch 'frozen-msystem-workaround' into 'meld-3-20'

[Kai Willadsen <kaiw src gnome org>]

commit b407eadad53a4ce7e97c93e5187628a7c2d45fa7
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Jan 10 05:02:13 2020 +0000

    Merge branch 'frozen-msystem-workaround' into 'meld-3-20'
    
    win32: workaround startup error with MSYSTEM env
    
    See merge request GNOME/meld!48
    
    (cherry picked from commit c5257d6223f77edc81acd7291f8ef35ca12a6827)
    
    23f84ea9 win32: workaround startup error with MSYSTEM env

 bin/meld | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)
---
diff --git a/bin/meld b/bin/meld
index 2e60a46d..95282642 100755
--- a/bin/meld
+++ b/bin/meld
@@ -408,10 +408,20 @@ def setup_glib_logging():
 
 
 def environment_hacks():
+    # MSYSTEM is set by git, and confuses our
+    # msys-packaged version's library search path -
+    # for frozen build the lib subdirectory is excluded.
+    # workaround it by adding as first path element.
+    # This may confuse vc utils run from meld
+    # but otherwise meld just crash on start, see #267
+
+    global frozen
+    if frozen and "MSYSTEM" in os.environ:
+        lib_dir = os.path.join(get_meld_dir(), "lib")
+        os.environ["PATH"] = lib_dir + os.pathsep + os.environ["PATH"]
     # We manage cwd ourselves for git operations, and GIT_DIR in particular
-    # can mess with this when set. MSYSTEM is set by git, and confuses our
-    # msys-packaged version's library search path.
-    for var in ('GIT_DIR', 'GIT_WORK_TREE', 'MSYSTEM'):
+    # can mess with this when set.
+    for var in ('GIT_DIR', 'GIT_WORK_TREE'):
         try:
             del os.environ[var]
         except KeyError: