.vs Visual Script file corrupting to RSCC

[sinaiyuc]

---

Bugsquad note: This issue has been confirmed several times already. No need to confirm it further.

---

Godot version:
3.1.1 and 3.2

OS/device including version:
Windows 10 and Mac OS 10.14.6

Issue description:
Visual Script files are becoming corrupted and the data disappears. This is bad because you lose your entire visual graph and there is no way to get it back. What happens is that when you open up one of the corrupted files a blank .vs file opens at the top of the list and the file itself opens in the code editor and just says "RSCC."

Steps to reproduce:
I am not sure exactly how to get the file to this state, but I have attached a minimal project below where there are 2 .vs files that are 1 version off of each other. I use Dropbox and so I can go back every time the file changes. One of the files doesn't corrupt (the one that has (1) at the end) and the other file will corrupt when you open up the file in GODOT. These files are 1 change apart from each other. So what ever I did to corrupt them I did right between. The next file (which I didn't include) is literally just RSCC with no other data in the file. Those 3 files all happened within minutes of each other.

I haven't been able to figure out exactly what causes the file to corrupt, but maybe someone smarter than me can see the difference between the two files and figure out what happened.

Minimal reproduction project:
InfiniteRunner copy.zip

[fire]

I tried recreating the problem and got this crash on start.

InfiniteRunner copy.zip

[akien-mga]

RSCC is the magic header for compressed resource files. So if the file only contains this, it means that it's basically empty, and thus invalid. So there might be two issues:

• Something is saving an invalid file/losing the contents
• FileAccessCompressed::open_after_magic needs better validity checks as seen in @fire's capture.

[fire]

This might be a clue to why it breaks:

Baroon ValmYesterday at 12:02

also i have almost nothing to contribute to the issue there as all useful info is basicly there.. tho there IS a way to get the code back, that nameless little VS that is loaded on top contains the "Broken" code, and also you can just Duplicate the code that is loaded in .txt or even rename it and open it and it'll be exactly like it should be

[akien-mga]

I tried to write some error handling to solve the crash reported by @fire, but I get more crashes further down the road due to bad handling of various FileAccess-derived pointers.

Leaving it at it for now, but in case someone wants to dig further:

diff --git a/core/io/file_access_compressed.cpp b/core/io/file_access_compressed.cpp
index 87ead37b91..345605f48a 100644
--- a/core/io/file_access_compressed.cpp
+++ b/core/io/file_access_compressed.cpp
@@ -64,6 +64,8 @@ Error FileAccessCompressed::open_after_magic(FileAccess *p_base) {
 	cmode = (Compression::Mode)f->get_32();
 	block_size = f->get_32();
 	read_total = f->get_32();
+	ERR_FAIL_COND_V_MSG(block_size == 0, ERR_INVALID_DATA,
+			"Can't open compressed file '" + f->get_path() + "' with block size 0, it is corrupted.");
 	int bc = (read_total / block_size) + 1;
 	int acc_ofs = f->get_position() + bc * 4;
 	int max_bs = 0;
@@ -125,13 +127,11 @@ Error FileAccessCompressed::_open(const String &p_path, int p_mode_flags) {
 		char rmagic[5];
 		f->get_buffer((uint8_t *)rmagic, 4);
 		rmagic[4] = 0;
-		if (magic != rmagic) {
+		if (magic != rmagic || open_after_magic(f) != OK) {
 			memdelete(f);
 			f = NULL;
 			return ERR_FILE_UNRECOGNIZED;
 		}
-
-		open_after_magic(f);
 	}
 
 	return OK;
diff --git a/core/io/resource_format_binary.cpp b/core/io/resource_format_binary.cpp
index 272d5c1116..27b2ea0a89 100644
--- a/core/io/resource_format_binary.cpp
+++ b/core/io/resource_format_binary.cpp
@@ -836,15 +836,19 @@ void ResourceInteractiveLoaderBinary::open(FileAccess *p_f) {
 	uint8_t header[4];
 	f->get_buffer(header, 4);
 	if (header[0] == 'R' && header[1] == 'S' && header[2] == 'C' && header[3] == 'C') {
-		//compressed
+		// Compressed.
 		FileAccessCompressed *fac = memnew(FileAccessCompressed);
-		fac->open_after_magic(f);
+		error = fac->open_after_magic(f);
+		if (error != OK) {
+			f->close();
+			memdelete(fac);
+			ERR_FAIL_MSG("Corrupted compressed binary resource file: " + local_path + ".");
+		}
 		f = fac;
-
 	} else if (header[0] != 'R' || header[1] != 'S' || header[2] != 'R' || header[3] != 'C') {
-		//not normal
-
+		// Not normal.
 		error = ERR_FILE_UNRECOGNIZED;
+		f->close();
 		ERR_FAIL_MSG("Unrecognized binary resource file: " + local_path + ".");
 	}
 
@@ -931,14 +935,19 @@ String ResourceInteractiveLoaderBinary::recognize(FileAccess *p_f) {
 	uint8_t header[4];
 	f->get_buffer(header, 4);
 	if (header[0] == 'R' && header[1] == 'S' && header[2] == 'C' && header[3] == 'C') {
-		//compressed
+		// Compressed.
 		FileAccessCompressed *fac = memnew(FileAccessCompressed);
-		fac->open_after_magic(f);
+		error = fac->open_after_magic(f);
+		if (error != OK) {
+			f->close();
+			memdelete(fac);
+			return "";
+		}
 		f = fac;
-
 	} else if (header[0] != 'R' || header[1] != 'S' || header[2] != 'R' || header[3] != 'C') {
-		//not normal
+		// Not normal.
 		error = ERR_FILE_UNRECOGNIZED;
+		f->close();
 		return "";
 	}
 
@@ -1043,26 +1052,29 @@ void ResourceFormatLoaderBinary::get_dependencies(const String &p_path, List<Str
 
 Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, const Map<String, String> &p_map) {
 
-	//Error error=OK;
-
 	FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
 	ERR_FAIL_COND_V_MSG(!f, ERR_CANT_OPEN, "Cannot open file '" + p_path + "'.");
 
-	FileAccess *fw = NULL; //=FileAccess::open(p_path+".depren");
+	FileAccess *fw = NULL;
 
 	String local_path = p_path.get_base_dir();
 
 	uint8_t header[4];
 	f->get_buffer(header, 4);
 	if (header[0] == 'R' && header[1] == 'S' && header[2] == 'C' && header[3] == 'C') {
-		//compressed
+		// Compressed.
 		FileAccessCompressed *fac = memnew(FileAccessCompressed);
-		fac->open_after_magic(f);
+		Error err = fac->open_after_magic(f);
+		if (err) {
+			f->close();
+			memdelete(fac);
+			ERR_FAIL_V_MSG(err, "Corrupted compressed binary resource file: " + local_path + ".");
+		}
 		f = fac;
 
 		FileAccessCompressed *facw = memnew(FileAccessCompressed);
 		facw->configure("RSCC");
-		Error err = facw->_open(p_path + ".depren", FileAccess::WRITE);
+		err = facw->_open(p_path + ".depren", FileAccess::WRITE);
 		if (err) {
 			memdelete(fac);
 			memdelete(facw);
@@ -1072,9 +1084,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 		fw = facw;
 
 	} else if (header[0] != 'R' || header[1] != 'S' || header[2] != 'R' || header[3] != 'C') {
-		//not normal
-
-		//error=ERR_FILE_UNRECOGNIZED;
+		// Not normal.
 		memdelete(f);
 		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unrecognized binary resource file '" + local_path + "'.");
 	} else {
@@ -1247,7 +1257,7 @@ String ResourceFormatLoaderBinary::get_resource_type(const String &p_path) const
 
 	FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
 	if (!f) {
-		return ""; //could not rwead
+		return ""; // Could not read.
 	}
 
 	Ref<ResourceInteractiveLoaderBinary> ria = memnew(ResourceInteractiveLoaderBinary);

[akien-mga]

Regarding the OP, the file is saved as a text file with "RSCC" probably because:

• The original file is corrupt, so the Visual Script editor refuses it
• It falls back to the text script editor, and only the "RSCC" ascii header makes sense to parse as text
• When saving the scene or closing the editor, the open file is saved by editor/plugins/script_editor_plugin.cpp::_save_text_file. The saved file is still in binary format, but only contains "RSCC" (the header magic for compressed binary resources).

So what would be needed is:

• Figuring out why the file is corrupt, and how to better handle it.
• Once properly identified as corrupt, don't open it as a text file.

And fixing the crash in any case on such an invalid file as per above comment.