GDScript formatted strings overwritten with old values when passed an empty array.

[Jack-023]

Tested versions

v4.3.stable.arch_linux

System information

Godot v4.3.stable unknown - Arch Linux #1 SMP PREEMPT_DYNAMIC Thu, 12 Sep 2024 17:21:02 +0000 - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3090 (nvidia; 560.35.03) - AMD Ryzen 7 5800X 8-Core Processor (16 Threads)

Issue description

When a formatted string using the % operator is given an empty array of arguments, it will replace the entire string (not just the placeholder) with the previous formatted string.

print("working %s string" % "formatted")
print("non-formatted string")
print("broken %s string" % [])

Will output

> working formatted string
> non-formatted string
> working formatted string

It does produce an error saying there are not enough arguments for the format string but it still runs and the output it produces is pretty confusing.

Steps to reproduce

See above.

Minimal reproduction project (MRP)

N/A

[matheusmdx]

Maybe a OS specific issue? Because here works as expected:

Godot v4.3.stable - Windows 10.0.19045 - Vulkan (Forward+) - dedicated AMD Radeon RX 580 2048SP (Advanced Micro Devices, Inc.; 31.0.21916.2) - AMD Ryzen 5 3600 6-Core Processor (12 Threads)

[akien-mga]

I can't reproduce the issue either on Linux. I get, as expected:

working formatted string
non-formatted string
ERROR: not enough arguments for format string
   at: validated_evaluate (core/variant/variant_op.h:951)

Godot v4.3.stable - Fedora Linux 40 (KDE Plasma) - Wayland - Vulkan (Forward+) - dedicated AMD Radeon RX 7600M XT (RADV NAVI33) - AMD Ryzen 7 7840HS w/ Radeon 780M Graphics (16 Threads)

Can you share an MRP that triggers that issue reliably for you?

[Jack-023]

Just realised I made a mistake when writing this up again. The value that gets substituted can't be hard-coded.

var foo := "foo"
print("%s bar" % foo)
print("hard coded values have no effect %s" % "baz")
print("this gets replaced by the first line %s" % [])

Output

foo bar
hard coded values have no effect baz
foo bar

Should have double checked this before posting, my bad!
edit: Here I am reading it from a var but this also happens if it were the return value from a function call. eg

print("%s bar" % foo())

[akien-mga]

I can confirm the issue with the code in #97176 (comment).
Pretty weird bug.

In the terminal, it prints:

foo bar
hard coded values have no effect baz
ERROR: not enough arguments for format string
   at: validated_evaluate (core/variant/variant_op.h:951)
foo bar

[aaronp64]

Looks like the same issue as #95152, should be fixed by #95166

[akien-mga]

Thanks, consolidating in #95152.