shell32: Make ShellExecute use native file association databases as fallback path (resend)

[Erik van Pienbroek]

Fixes http://bugs.winehq.org/show_bug.cgi?id=12464
Based on initial work from Jeff Miller

The ShellExecute and related functions currently only search
for known file assocations inside the wine prefix. When an
attempt to done to open a file of which there is no registered
file association inside the wine prefix the ShellExecute call
will fail. This change adds a fallback path where an attempt is
done to open a file using the native file association databases
before giving up. On Linux environments one of the tools 'xdg-open',
'gnome-open' or 'kde-open' is used (depending on the environment).
For Mac OS X environments the tool 'open' is used

Additionally a check is added to make sure no recursive loop is triggered
when the native file association database points back to wine and the
fallback path is triggered again

Tested succesfully on a Fedora 17 environment using the start.exe
command and Outlook 2007 by trying to open a .pdf file (where there
is no file association registered inside the wine prefix)
---
 dlls/shell32/shlexec.c |   81 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/dlls/shell32/shlexec.c b/dlls/shell32/shlexec.c
index 77212f0..e4c24f7 100644
--- a/dlls/shell32/shlexec.c
+++ b/dlls/shell32/shlexec.c
@@ -26,11 +26,15 @@
 #include <string.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <errno.h>
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
 #include <ctype.h>
 #include <assert.h>
+#ifdef HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
 
 #define COBJMACROS
 
@@ -1554,6 +1558,48 @@ static void do_error_dialog( UINT_PTR retval, HWND hwnd )
     MessageBoxW(hwnd, msg, NULL, MB_ICONERROR);
 }
 
+#if defined(HAVE_FORK) && defined(HAVE_WAITPID)
+static UINT_PTR SHELL_try_native_execute ( const char *openCmd, const char *unixName )
+{
+    UINT_PTR retval = SE_ERR_NOASSOC;
+    pid_t cpid;
+    struct stat st;
+
+    if (stat(openCmd, &st) == -1)
+    {
+        TRACE("stat() %s failed: %s\n", openCmd, strerror(errno));
+        return retval;
+    }
+
+    cpid = fork();
+    if (!cpid)
+    {
+        /* Prevent the situation where the native file association database
+         * tries to run wine to execute a program and we trigger this fallback
+         * path again and end up in a recursive loop */
+        if (getenv("WINE_INSIDE_SHELLEXECUTE"))
+        {
+            TRACE("recursive loop detected, not continuing with ShellExecute call\n");
+            exit(EXIT_SUCCESS);
+        }
+        setenv("WINE_INSIDE_SHELLEXECUTE", "1", 0);
+
+        TRACE("running %s %s\n", openCmd, unixName);
+        execlp(openCmd, openCmd, unixName, (char*) NULL);
+        /* execlp replaces the current process image with a new process image,
+         * so no code below here should get executed by the forked child */
+    } else {
+        int status;
+        waitpid(cpid, &status, 0);
+        TRACE("status %x\n", status);
+        if(!WEXITSTATUS(status))
+            retval = 33;
+    }
+
+    return retval;
+}
+#endif
+
 /*************************************************************************
  *	SHELL_execute [Internal]
  */
@@ -1911,6 +1957,41 @@ static BOOL SHELL_execute( LPSHELLEXECUTEINFOW sei, SHELL_ExecuteW32 execfunc )
         strcatW(lpstrTmpFile, lpFile);
         retval = (UINT_PTR)ShellExecuteW(sei_tmp.hwnd, sei_tmp.lpVerb, lpstrTmpFile, NULL, NULL, 0);
     }
+#if defined(HAVE_FORK) && defined(HAVE_WAITPID)
+    /* Integration with native file association database */
+    else 
+    {
+        char * unixName;
+        LPSTR (*wine_get_unix_file_name_ptr)(LPCWSTR) = NULL;
+
+        wine_get_unix_file_name_ptr = (void*)
+            GetProcAddress(GetModuleHandleA("KERNEL32"),
+                           "wine_get_unix_file_name");
+
+        unixName = wine_get_unix_file_name_ptr(lpFile);
+
+#ifdef __APPLE__
+        retval = SHELL_try_native_execute("/usr/bin/open", unixName);
+#else
+        /* Try to use xdg-open to execute the file first */
+        retval = SHELL_try_native_execute("/usr/bin/xdg-open", unixName);
+        if (retval == SE_ERR_NOASSOC)
+        {
+            /* xdg-open could not be found, try to detect the desktop environment */
+            if (getenv("KDE_FULL_SESSION"))
+            {
+                retval = SHELL_try_native_execute("/usr/bin/kde-open", unixName);
+            }
+            else if (getenv("GNOME_DESKTOP_SESSION_ID"))
+            {
+                retval = SHELL_try_native_execute("/usr/bin/gnome-open", unixName);
+            }
+        }
+#endif
+
+        HeapFree(GetProcessHeap(), 0, unixName);
+    }
+#endif
 
     TRACE("retval %lu\n", retval);
 
-- 
1.7.10.4