Fix environment case sensitivity issues on Windows

2 files changed, 23 insertions, 3 deletions

diff --git a/erts/emulator/sys/common/erl_osenv.c b/erts/emulator/sys/common/erl_osenv.c
index 9f54d1dff0..487ff87116 100644
--- a/erts/emulator/sys/common/erl_osenv.c
+++ b/erts/emulator/sys/common/erl_osenv.c
@@ -75,7 +75,15 @@ static int compare_env_keys(const erts_osenv_data_t a, const erts_osenv_data_t b
 #include "erl_rbtree.h"
 
 static int compare_env_keys(const erts_osenv_data_t a, const erts_osenv_data_t b) {
-    int relation = sys_memcmp(a.data, b.data, MIN(a.length, b.length));
+    int relation;
+
+#ifdef __WIN32__
+    /* Environment variables are case-insensitive on Windows. */
+    relation = _wcsnicmp((const WCHAR*)a.data, (const WCHAR*)b.data,
+                         MIN(a.length, b.length) / sizeof(WCHAR));
+#else
+    relation = sys_memcmp(a.data, b.data, MIN(a.length, b.length));
+#endif
 
     if(relation != 0) {
         return relation;
diff --git a/erts/emulator/test/bif_SUITE.erl b/erts/emulator/test/bif_SUITE.erl
index 32bfcd5520..9e7bcd5255 100644
--- a/erts/emulator/test/bif_SUITE.erl
+++ b/erts/emulator/test/bif_SUITE.erl
@@ -36,7 +36,8 @@
 	 error_stacktrace_during_call_trace/1,
          group_leader_prio/1, group_leader_prio_dirty/1,
          is_process_alive/1,
-         process_info_blast/1]).
+         process_info_blast/1,
+         os_env_case_sensitivity/1]).
 
 suite() ->
     [{ct_hooks,[ts_install_cth]},
@@ -51,7 +52,7 @@ all() ->
      erl_crash_dump_bytes, min_max, erlang_halt, is_builtin,
      error_stacktrace, error_stacktrace_during_call_trace,
      group_leader_prio, group_leader_prio_dirty,
-     is_process_alive, process_info_blast].
+     is_process_alive, process_info_blast, os_env_case_sensitivity].
 
 %% Uses erlang:display to test that erts_printf does not do deep recursion
 display(Config) when is_list(Config) ->
@@ -443,6 +444,17 @@ os_env_long(Min, Max, Value) ->
     true = os:unsetenv(EnvVar),
     os_env_long(Min+1, Max, Value).
 
+os_env_case_sensitivity(Config) when is_list(Config) ->
+    %% The keys in os:getenv/putenv must be case-insensitive on Windows, and
+    %% case-sensitive elsewhere.
+    true = os:putenv("os_env_gurka", "gaffel"),
+    Expected = case os:type() of
+                   {win32, _} -> "gaffel";
+                   _ -> false
+               end,
+    Expected = os:getenv("OS_ENV_GURKA"),
+    ok.
+
 %% Test that string:to_integer does not Halloc in wrong order.
 otp_7526(Config) when is_list(Config) ->
     ok = test_7526(256).