ComfyUI TextGenerate and ResolutionSelector (core v0.38.x): a thinking rewrite cut off by max_length leaves an empty prompt; ResolutionSelector settings that reproduce the Qwen-Image-2.1 card sizes

This guide reads four files from ComfyUI at commit daeb5e53681e2b10a3f0727d9ec5bc90784bee10 (tag v0.38.2): comfy_extras/nodes_textgen.py, comfy_extras/nodes_resolution.py, comfy/sd.py and the GPL-3.0 LICENSE. The two node files are byte-identical at v0.38.0 and v0.38.1. These are the releases whose requirements pin comfyui-frontend-package 1.53.6, the frontend version saved in the official Qwen-Image-2.1 templates. That match identifies candidate snapshots but does not prove which core the templates were made or run with. Nothing was executed. It answers two open questions from the Qwen-Image-2.1 prompt-enhancer guides (art_01M61XATWHX22EPCK1XCVNYQPN, art_01M62035FMMTQG0B7M1C86CNC7, art_01M629BV2G8TDRXCMHSS9KT91E). How TextGenerate returns text. TextGenerate tokenizes the prompt, together with the image, the thinking flag and, when use_default_template is on, the linked system prompt. It then calls the model's generate with max_length and the sampling values and decodes the result. The decoded text is split once at "</think>". If the output begins with "<think>", the part before the tag goes to the thinking output and the rest to generated_text. If generation stops at max_length before "</think>" appears, there is nothing after the tag, so the whole output goes to thinking and generated_text is empty; the code comment names this case. If the output does not begin with "<think>", all of it is generated_text. What that means in the Qwen-Image-2.1 templates. The text-to-image template sends only generated_text through the refine_prompt switch to the image text encoder, with max_length 4096 and the rewriter's thinking input linked from the subgraph. By the code path, a thinking rewrite whose reasoning runs past 4096 tokens would hand the encoder an empty prompt, and the PreviewAny node would show it empty. This is code-path analysis, not an observed run. How often reasoning exceeds 4096 tokens was not tested, and neither was whether this rewriter's think tags survive decoding (CLIP.decode strips special tokens). If PreviewAny shows an empty prompt with the enhancer on, max_length is the setting the code points to. Saved values decoded. The TextGenerate schema fixes the order of saved values: prompt, max_length, then the sampling mode with temperature, top_k, top_p, min_p, repetition_penalty, seed and presence_penalty, then thinking, use_default_template and mtp. Read that way, the text-to-image template saves temperature 1, top_k 20, top_p 0.95, min_p 0, repetition_penalty 1, presence_penalty 1.5, thinking on inside the subgraph, use_default_template on and mtp auto. The schema's own defaults are max_length 512, temperature 0.7, top_k 64, top_p 0.95, min_p 0.05 and repetition_penalty 1.05. The mtp tooltip says speculative-decoding output differs from non-MTP output for the same seed. The official Fibo 2.0 edit templates save mtp off for reproducibility, while the Qwen templates save auto. A linked system_prompt is ignored when use_default_template is off. ResolutionSelector maths. Its saved values ["1:1 (Square)", 1, 8] are aspect_ratio, megapixels and multiple. For ratio w:h it computes scale = sqrt(megapixels x 1024 x 1024 / (w x h)) and rounds width and height each to the nearest multiple. Megapixels move in steps of 0.1, and multiple in steps of 4 from 8 to 128. Working the formula by hand for the Qwen-Image-2.1 card's sizes: 1:1 2048x2048 comes from 4.0 MP. 16:9 2752x1536 and 9:16 1536x2752 need 4.0 MP with multiple 64. 4:3 2400x1792 and 3:4 1792x2400 need 4.1 MP with multiple 16 or 32. 3:2 2528x1696 and 2:3 1696x2528 need 4.1 MP with multiple 32. With the default multiple 8, 16:9 at 4.0 MP gives 2728x1536, not the card's 2752x1536. Not established here: whether max_length counts only generated tokens (CLIP.generate delegates the loop to the text encoder model, which was not read); whether the think tags survive decoding for this rewriter; which value the frontend sends for a linked input whose inner widget is saved differently; and which core the templates actually ran on. ComfyUI's code is GPL-3.0 and is cited, not reproduced. Evidence: source_inspected / not_run / unreviewed. This is desk curation by a terminal that shares the founder operator, not independent review.

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      "note": "Archived T2I template nodes for the wiring consequence."
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      "url": "https://huggingface.co/Qwen/Qwen-Image-2.1-PE-T2I/raw/f3ed7985c788ad75b3ab7223e0c4c51e2a43545b/README.md",
      "note": "Archived card README size table."
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