Commit bf1cbebea1

@@ -927,6 +927,24 @@ pub fn sliceToPrefixedFileW(s: []const u8) ![PATH_MAX_WIDE + 1]u16 {
     return sliceToPrefixedSuffixedFileW(s, [_]u16{0});
 }
 
+/// Assumes an absolute path.
+pub fn wToPrefixedFileW(s: []const u16) ![PATH_MAX_WIDE + 1]u16 {
+    // TODO https://github.com/ziglang/zig/issues/2765
+    var result: [PATH_MAX_WIDE + 1]u16 = undefined;
+
+    const start_index = if (mem.startsWith(u16, s, [_]u16{'\\', '?'})) 0 else blk: {
+        const prefix = [_]u16{ '\\', '?', '?', '\\' };
+        mem.copy(u16, result[0..], prefix);
+        break :blk prefix.len;
+    };
+    const end_index = start_index + s.len;
+    if (end_index + 1 > result.len) return error.NameTooLong;
+    mem.copy(u16, result[start_index..], s);
+    result[end_index] = 0;
+    return result;
+
+}
+
 pub fn sliceToPrefixedSuffixedFileW(s: []const u8, comptime suffix: []const u16) ![PATH_MAX_WIDE + suffix.len]u16 {
     // TODO https://github.com/ziglang/zig/issues/2765
     var result: [PATH_MAX_WIDE + suffix.len]u16 = undefined;
@@ -948,7 +966,6 @@ pub fn sliceToPrefixedSuffixedFileW(s: []const u8, comptime suffix: []const u16)
         break :blk prefix.len;
     };
     const end_index = start_index + try std.unicode.utf8ToUtf16Le(result[start_index..], s);
-    assert(end_index <= result.len);
     if (end_index + suffix.len > result.len) return error.NameTooLong;
     mem.copy(u16, result[end_index..], suffix);
     return result;

@@ -1243,9 +1243,9 @@ pub fn openSelfExe() OpenSelfExeError!File {
         return File.openReadC(c"/proc/self/exe");
     }
     if (builtin.os == .windows) {
-        var buf: [os.windows.PATH_MAX_WIDE]u16 = undefined;
-        const wide_slice = try selfExePathW(&buf);
-        return File.openReadW(wide_slice.ptr);
+        const wide_slice = selfExePathW();
+        const prefixed_path_w = try os.windows.wToPrefixedFileW(wide_slice);
+        return Dir.cwd().openReadW(&prefixed_path_w);
     }
     var buf: [MAX_PATH_BYTES]u8 = undefined;
     const self_exe_path = try selfExePath(&buf);
@@ -1296,8 +1296,7 @@ pub fn selfExePath(out_buffer: *[MAX_PATH_BYTES]u8) SelfExePathError![]u8 {
             return mem.toSlice(u8, out_buffer);
         },
         .windows => {
-            var utf16le_buf: [os.windows.PATH_MAX_WIDE]u16 = undefined;
-            const utf16le_slice = try selfExePathW(&utf16le_buf);
+            const utf16le_slice = selfExePathW();
             // Trust that Windows gives us valid UTF-16LE.
             const end_index = std.unicode.utf16leToUtf8(out_buffer, utf16le_slice) catch unreachable;
             return out_buffer[0..end_index];
@@ -1306,9 +1305,10 @@ pub fn selfExePath(out_buffer: *[MAX_PATH_BYTES]u8) SelfExePathError![]u8 {
     }
 }
 
-/// Same as `selfExePath` except the result is UTF16LE-encoded.
-pub fn selfExePathW(out_buffer: *[os.windows.PATH_MAX_WIDE]u16) SelfExePathError![]u16 {
-    return os.windows.GetModuleFileNameW(null, out_buffer, out_buffer.len);
+/// The result is UTF16LE-encoded.
+pub fn selfExePathW() []const u16 {
+    const image_path_name = &os.windows.peb().ProcessParameters.ImagePathName;
+    return mem.toSliceConst(u16, image_path_name.Buffer);
 }
 
 /// `selfExeDirPath` except allocates the result on the heap.