LM (Linux): try fixing LightDM version detection

src/common/processing_windows.c

@@ -11,18 +11,18 @@ const char* ffProcessAppendStdOut(FFstrbuf* buffer, char* const argv[])
         .bInheritHandle = TRUE,
     };
 
-    HANDLE hChildStdoutRead, hChildStdoutWrite;
-    if (!CreatePipe(&hChildStdoutRead, &hChildStdoutWrite, &saAttr, 0))
+    HANDLE hChildPipeRead, hChildPipeWrite;
+    if (!CreatePipe(&hChildPipeRead, &hChildPipeWrite, &saAttr, 0))
         return "CreatePipe() failed";
 
-    if (!SetHandleInformation(hChildStdoutRead, HANDLE_FLAG_INHERIT, 0))
-        return "SetHandleInformation(hChildStdoutRead) failed";
+    if (!SetHandleInformation(hChildPipeRead, HANDLE_FLAG_INHERIT, 0))
+        return "SetHandleInformation(hChildPipeRead) failed";
 
     PROCESS_INFORMATION piProcInfo = {0};
     STARTUPINFOA siStartInfo = {
         .cb = sizeof(siStartInfo),
         .dwFlags = STARTF_USESTDHANDLES,
-        .hStdOutput = hChildStdoutWrite,
+        .hStdOutput = hChildPipeWrite,
     };
 
     BOOL success;
@@ -49,18 +49,80 @@ const char* ffProcessAppendStdOut(FFstrbuf* buffer, char* const argv[])
         );
     }
 
-    CloseHandle(hChildStdoutWrite);
+    CloseHandle(hChildPipeWrite);
     if(!success)
     {
-        CloseHandle(hChildStdoutRead);
+        CloseHandle(hChildPipeRead);
         return "CreateProcessA() failed";
     }
 
     char str[1024];
     DWORD nRead;
-    while(ReadFile(hChildStdoutRead, str, sizeof(str), &nRead, NULL) && nRead > 0)
+    while(ReadFile(hChildPipeRead, str, sizeof(str), &nRead, NULL) && nRead > 0)
         ffStrbufAppendNS(buffer, nRead, str);
 
-    CloseHandle(hChildStdoutRead);
+    CloseHandle(hChildPipeRead);
+    return NULL;
+}
+
+const char* ffProcessAppendStdErr(FFstrbuf* buffer, char* const argv[])
+{
+    SECURITY_ATTRIBUTES saAttr = {
+        .nLength = sizeof(SECURITY_ATTRIBUTES),
+        .lpSecurityDescriptor = NULL,
+        .bInheritHandle = TRUE,
+    };
+
+    HANDLE hChildPipeRead, hChildPipeWrite;
+    if (!CreatePipe(&hChildPipeRead, &hChildPipeWrite, &saAttr, 0))
+        return "CreatePipe() failed";
+
+    if (!SetHandleInformation(hChildPipeRead, HANDLE_FLAG_INHERIT, 0))
+        return "SetHandleInformation(hChildPipeRead) failed";
+
+    PROCESS_INFORMATION piProcInfo = {0};
+    STARTUPINFOA siStartInfo = {
+        .cb = sizeof(siStartInfo),
+        .dwFlags = STARTF_USESTDHANDLES,
+        .hStdError = hChildPipeWrite,
+    };
+
+    BOOL success;
+
+    {
+        FF_STRBUF_AUTO_DESTROY cmdline = ffStrbufCreateF("\"%s\"", argv[0]);
+        for(char* const* parg = &argv[1]; *parg; ++parg)
+        {
+            ffStrbufAppendC(&cmdline, ' ');
+            ffStrbufAppendS(&cmdline, *parg);
+        }
+
+        success = CreateProcessA(
+            NULL,          // application name
+            cmdline.chars, // command line
+            NULL,          // process security attributes
+            NULL,          // primary thread security attributes
+            TRUE,          // handles are inherited
+            0,             // creation flags
+            NULL,          // use parent's environment
+            NULL,          // use parent's current directory
+            &siStartInfo,  // STARTUPINFO pointer
+            &piProcInfo    // receives PROCESS_INFORMATION
+        );
+    }
+
+    CloseHandle(hChildPipeWrite);
+    if(!success)
+    {
+        CloseHandle(hChildPipeRead);
+        return "CreateProcessA() failed";
+    }
+
+    char str[1024];
+    DWORD nRead;
+    while(ReadFile(hChildPipeRead, str, sizeof(str), &nRead, NULL) && nRead > 0)
+        ffStrbufAppendNS(buffer, nRead, str);
+
+    CloseHandle(hChildPipeRead);
     return NULL;
 }