From f434a98c26b5cd2ad67a4f4ae67065cf4a6b8299 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Mon, 29 Oct 2018 20:00:03 -0400
Subject: [PATCH] winmain: Don't use SDL_malloc (or SDL_stack_alloc, which
 might be malloc).

Otherwise, we are using the allocator before the app can set up its own hooks.

Now we use VirtualAlloc, and WideCharToMultiByte (because SDL_iconv uses
SDL_malloc, too!) to get ready to call into SDL_main.

This also makes console_wmain() call into the same routines as everything
else, so we don't have to deal with those allocations, too. Hopefully we
end up with the same results from GetCommandLine() as we do in wargv.

Fixes Bugzilla #4340.
---
 src/main/windows/SDL_windows_main.c | 81 +++++++++++++++--------------
 1 file changed, 41 insertions(+), 40 deletions(-)

diff --git a/src/main/windows/SDL_windows_main.c b/src/main/windows/SDL_windows_main.c
index 5e643a44b..039503224 100644
--- a/src/main/windows/SDL_windows_main.c
+++ b/src/main/windows/SDL_windows_main.c
@@ -116,50 +116,65 @@ OutOfMemory(void)
 # endif
 #endif
 
-/* WinMain, main, and wmain eventually call into here. */
-static int
-main_utf8(int argc, char *argv[])
-{
-    SDL_SetMainReady();
-
-    /* Run the application main() code */
-    return SDL_main(argc, argv);
-}
-
 /* Gets the arguments with GetCommandLine, converts them to argc and argv
-   and calls main_utf8 */
+   and calls SDL_main */
 static int
 main_getcmdline()
 {
     char **argv;
     int argc;
-    char *cmdline;
+    char *cmdline = NULL;
     int retval = 0;
+    int cmdalloc = 0;
+    const TCHAR *text = GetCommandLine();
+    const TCHAR *ptr;
+    int argc_guess = 2;  /* space for NULL and initial argument. */
+    int rc;
+
+    /* make a rough guess of command line arguments. Overestimates if there
+       are quoted things. */
+    for (ptr = text; *ptr; ptr++) {
+        if ((*ptr == ' ') || (*ptr == '\t')) {
+            argc_guess++;
+        }
+    }
 
-    /* Grab the command line */
-    TCHAR *text = GetCommandLine();
 #if UNICODE
-    cmdline = WIN_StringToUTF8(text);
+    rc = WideCharToMultiByte(CP_UTF8, 0, text, -1, NULL, 0, NULL, NULL);
+    if (rc > 0) {
+        cmdalloc = rc + (sizeof (char *) * argc_guess);
+        argv = (char **) VirtualAlloc(NULL, cmdalloc, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
+        if (argv) {
+            cmdline = (char *) (argv + argc_guess);
+            const int rc2 = WideCharToMultiByte(CP_UTF8, 0, text, -1, cmdline, rc, NULL, NULL);
+            SDL_assert(rc2 == rc);
+        }
+    }
 #else
     /* !!! FIXME: are these in the system codepage? We need to convert to UTF-8. */
-    cmdline = SDL_strdup(text);
+    rc = ((int) SDL_strlen(text)) + 1;
+    cmdalloc = rc + (sizeof (char *) * argc_guess);
+    argv = (char **) VirtualAlloc(NULL, cmdalloc, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE);
+    if (argv) {
+        cmdline = (char *) (argv + argc_guess);
+        SDL_strcpy(cmdline, text);
+    }
 #endif
     if (cmdline == NULL) {
         return OutOfMemory();
     }
 
     /* Parse it into argv and argc */
-    argc = ParseCommandLine(cmdline, NULL);
-    argv = SDL_stack_alloc(char *, argc + 1);
-    if (argv == NULL) {
-        return OutOfMemory();
-    }
-    ParseCommandLine(cmdline, argv);
+    SDL_assert(ParseCommandLine(cmdline, NULL) <= argc_guess);
+    argc = ParseCommandLine(cmdline, argv);
 
-    retval = main_utf8(argc, argv);
+    SDL_SetMainReady();
 
-    SDL_stack_free(argv);
-    SDL_free(cmdline);
+    /* Run the application main() code */
+    retval = SDL_main(argc, argv);
+
+    VirtualFree(argv, cmdalloc, MEM_DECOMMIT);
+    VirtualFree(argv, 0, MEM_RELEASE);
 
     return retval;
 }
@@ -177,21 +192,7 @@ console_ansi_main(int argc, char *argv[])
 int
 console_wmain(int argc, wchar_t *wargv[], wchar_t *wenvp)
 {
-    int retval = 0;
-    char **argv = SDL_stack_alloc(char*, argc + 1);
-    int i;
-
-    for (i = 0; i < argc; ++i) {
-        argv[i] = WIN_StringToUTF8(wargv[i]);
-    }
-    argv[argc] = NULL;
-
-    retval = main_utf8(argc, argv);
-
-    /* !!! FIXME: we are leaking all the elements of argv we allocated. */
-    SDL_stack_free(argv);
-
-    return retval;
+    return main_getcmdline();
 }
 #endif