bug#59979: 30.0.50; dockerfile-ts-mode imenu issue

[Randy Taylor]

On Sunday, December 11th, 2022 at 15:39, Eshel Yaron via "Bug reports for GNU 
Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org> wrote:
> 
> I stumbled upon the following issue while checking out the new
> dockerfile-ts-mode.
> 
> 1. emacs -Q
> 2. C-x C-f /tmp/Dockerfile
> 3. Insert the following contents (taken from
> https://docs.docker.com/build/building/multi-stage/#use-a-previous-stage-as-a-new-stage):
> 
> FROM ubuntu AS base
> RUN echo "base"
> 
> FROM base AS stage1
> RUN echo "stage1"
> 
> FROM base AS stage2
> RUN echo "stage2"
> 
> 4. Try to use M-x imenu to navigate to the last build stage
> 4.a. We get the following imenu--index-alist:
> 
> (("Stage"
> ("ubuntu" . #<marker at 1 in Dockerfile>)
> 
> ("base" . #<marker at 42 in Dockerfile>)
> 
> ("base" . #<marker at 81 in Dockerfile>)))
> 
> 
> 4.b. Consequently, we can't choose and jump to the last stage, because
> dockerfile-ts-mode calls both of the last two stages by the same name
> ("base").
> 
> The crux of the issue is that dockerfile-ts-mode uses a stage's base
> image as its name, which seems kinda wrong and leads to ambiguity since
> many stages can have a common base image. Instead, it would be
> preferable IMO to use the index of the stage or, when available, its
> unique name (such as "stage1" in the example above).
> 
> Thanks!
> 

Thanks, I'll take a look and hopefully reply back with a patch in a bit.