Hello both Nicolas, Nicolas Richard wrote: > Sebastien Vauban writes: >> I tried to edebug the function `org-babel-demarcate-block' and the >> error arises quite at the beginning: on the `match-string 0', on the >> second line of the `let*'. > > The error means we tried to access portions from 0 to 1 in a buffer. > That doesn't exist. The reason is that the match data was built when > matching on a string (where 0 is a valid position), and we're trying > to use it on a buffer. It simply means that we're trying to access the > match data without actually checking that we matched something. > > Reproduce with: > (progn (string-match "\\(\\(\\(\\(.\\)\\)\\)\\)" "foo") ; this sets the match > data > (with-temp-buffer > (org-babel-demarcate-block))) ; tries to access the match data, > ; but never matched anything > successfully > >> - I can't reproduce it in a minimal Emacs, and there... edebug ends >> in an error (I wanted to compare the execution steps), as you can see >> on the right screen of http://screencast.com/t/A5ldV2yHNna. >> >> Why is edebug crashing? > > Did you perhaps kill the buffer where org-babel-demarcate-block was > instrumented for edebug ?
I cannot exclude that. In the minimal Emacs, I loose so many effective key bindings that it takes me a while to do what I want to do ;-) >> - It seems normal that `org-babel-where-is-src-block-head' returns >> nil when we use `C-c C-v C-d' to create the first code block in >> a buffer which did not contain any... and it works in my minimal >> Emacs... (iff edebug is turned off) >> >> Any idea of the problem, then? > > I think the `progn' in org-babel-demarcate-block should be `and'. > > (I also think that the fact that the match data is set according to > org-babel-src-block-regexp when calling > org-babel-where-is-src-block-head should be documented in that > function. Relying on undocumented side effects is nasty.) Thanks for the explanation. This still leaves me with one question: how do we reproduce the problem? What's the trigger for it? PS- @NicolasG, thanks for fixing it... Best regards, Seb -- Sebastien Vauban
