gpgconf: Improve registry dumping.

* common/w32-reg.c (read_w32_reg_string): Add arg r_hklm_fallback and
change all callers.
(show_configs): Indicate whether the HKLM fallback was used.
* tools/gpgconf.c (show_other_registry_entries): Fix the Outlook Addin
Registry key.  Indicate whether the HKLM fallback was used.
--

Note that this is  backport from 2.2.  The new support there for
REG_DWORD needs to be implemented in libgpg-error, though.

common/t-w32-reg.c

@@ -56,7 +56,7 @@ test_read_registry (void)
 
   string2 = read_w32_reg_string
     ("HKCU\\Software\\Microsoft\\Windows\\CurrentVersion"
-     "\\Internet Settings:User Agent");
+     "\\Internet Settings:User Agent", NULL);
   if (!string2)
     fail (1);
   fprintf (stderr, "User agent: %s\n", string2);
@@ -76,7 +76,7 @@ main (int argc, char **argv)
 {
   if (argc > 1)
     {
-      char *string = read_w32_reg_string (argv[1]);
+      char *string = read_w32_reg_string (argv[1], NULL);
       printf ("%s -> %s\n", argv[1], string? string : "(null)");
       xfree (string);
     }

common/w32-reg.c

@@ -71,14 +71,19 @@ read_w32_registry_string (const char *root, const char *dir, const char *name)
  *
  * Note that the first backslash and the first colon act as delimiters.
  *
- * Returns a malloced string or NULL if not found.
+ * Returns a malloced string or NULL if not found.  If R_HKLM_FALLBACK
+ * is not NULL, no class was given, and the result came from HKLM,
+ * true is stored there.
  */
 char *
-read_w32_reg_string (const char *key_arg)
+read_w32_reg_string (const char *key_arg, int *r_hklm_fallback)
 {
   char *key;
   char *p1, *p2;
-  char *result;
+  char *result, *result2;
+
+  if (r_hklm_fallback)
+    *r_hklm_fallback = 0;
 
   if (!key_arg)
     return NULL;
@@ -101,6 +106,15 @@ read_w32_reg_string (const char *key_arg)
     *p2++ = 0;
 
   result = gpgrt_w32_reg_query_string (*key? key : NULL, p1, p2);
+  if (result && !*key && r_hklm_fallback)
+    {
+      /* No key given - see whether the result came from HKCU or HKLM.  */
+      result2 = gpgrt_w32_reg_query_string ("HKCU", p1, p2);
+      if (result2)
+        xfree (result2);
+      else
+        *r_hklm_fallback = 1;
+    }
   xfree (key);
   return result;
 }

common/w32help.h

@@ -44,7 +44,7 @@ char **w32_parse_commandline (char *cmdline, int globing, int *r_argv,
 /*-- w32-reg.c --*/
 char *read_w32_registry_string (const char *root,
 				const char *dir, const char *name );
-char *read_w32_reg_string (const char *key);
+char *read_w32_reg_string (const char *key, int *r_hklm_fallback);
 
 
 #endif /*HAVE_W32_SYSTEM*/