[Emacs-diffs] master cbbea70 3/5: addpm.c: Replace existing entries, but do not create new ones

[Juanma Barranquero]

branch: master
commit cbbea701c6956961b55ed754fbfe2ae6329f940b
Author: Juanma Barranquero <address@hidden>
Commit: Juanma Barranquero <address@hidden>

    addpm.c: Replace existing entries, but do not create new ones
    
    * nt/addpm.c (add_registry): If the Emacs registry key exists, replace
    existing values from previous versions, but do not add new ones; the
    key could exist for other reasons unrelated to old Emacsen, like X-style
    resources, or to set some environment variables like HOME or LANG, and
    in that case we don't want to populate it with obsolete values.
---
 nt/addpm.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/nt/addpm.c b/nt/addpm.c
index ba0eb36..caa3272 100644
--- a/nt/addpm.c
+++ b/nt/addpm.c
@@ -186,17 +186,20 @@ add_registry (const char *path)
      have any resources.  */
 
   if (RegOpenKeyEx (HKEY_LOCAL_MACHINE, REG_ROOT, 0,
-                     KEY_WRITE, &hrootkey) != ERROR_SUCCESS
+                   KEY_WRITE | KEY_QUERY_VALUE, &hrootkey) != ERROR_SUCCESS
       && RegOpenKeyEx (HKEY_CURRENT_USER, REG_ROOT, 0,
-                        KEY_WRITE, &hrootkey) != ERROR_SUCCESS)
+                      KEY_WRITE | KEY_QUERY_VALUE, &hrootkey) != ERROR_SUCCESS)
     return;
 
   for (i = 0; i < (sizeof (env_vars) / sizeof (env_vars[0])); i++)
     {
       const char * value = env_vars[i].value ? env_vars[i].value : path;
 
-      RegSetValueEx (hrootkey, env_vars[i].name, 0, REG_EXPAND_SZ,
-                    value, lstrlen (value) + 1);
+      /* Replace only those settings that already exist.  */
+      if (RegQueryValueEx (hrootkey, env_vars[i].name, NULL,
+                          NULL, NULL, NULL) == ERROR_SUCCESS)
+       RegSetValueEx (hrootkey, env_vars[i].name, 0, REG_EXPAND_SZ,
+                      value, lstrlen (value) + 1);
     }
 
   RegCloseKey (hrootkey);