Better REGEX in navit/xpm/CMakeLists.txt

[tobe deprez]

In the file navit/xpm/CMakeLists.txt, there is some code to detect the width of the svg file (line 21-24):

if (${SCALE} EQUAL 0)
  file(STRINGS  ${IMAGE_INPUT} NEW_SCALE_LINE REGEX "[^-]width=\"[0-9pxt.]*\"")
  string(REGEX REPLACE ".*width=\"([0-9]*).*" "\\1" NEW_SCALE ${NEW_SCALE_LINE})
endif()

This code does not seem to work for some files (museum.svg and hotel.svg if I remember correctly): the ${NEW_SCALE} variable was 0. I don't know exactly what happened, but I think the code read some other width attribute somewhere the svg file. To avoid this, you can use the following code, which specifically tries to read the width attribute in the <svg> tag:

if (${SCALE} EQUAL 0)
  file (READ ${IMAGE_INPUT} IMAGE_CONTENTS)
  string(REGEX MATCH "<svg[^>-]*width=\"([0-9]+)(px)?\"[^>]*>" SVG_TAG "${IMAGE_CONTENTS}")
  set (NEW_SCALE "${CMAKE_MATCH_1}")
endif()

[tobe deprez]

Somehow a superfluous '-' crept in my code above. It should have been

if (${SCALE} EQUAL 0)
  file (READ ${IMAGE_INPUT} IMAGE_CONTENTS)
  string(REGEX MATCH "<svg[^>]*width=\"([0-9]+)(px)?\"[^>]*>" SVG_TAG "${IMAGE_CONTENTS}")
  set (NEW_SCALE "${CMAKE_MATCH_1}")
endif()

[davo]

Ah, I spent several hours working out what was happening during my install, should have looked here first. Anyway, more info - The problem happens because some SVG files mention "width=" more than once, the author assumed there would be only one instance in the strings output. I am pretty sure that the first instance is always the right one, so all that needs happen is to add an option to the cmake strings command, "LIMIT_COUNT 1" so it returns the first one it finds. Easier than changing the regex ....

So line 23 of CMakeLists.txt in xpm directory becomes -

file(STRINGS  ${IMAGE_INPUT} NEW_SCALE_LINE LIMIT_COUNT 1 REGEX "[^-]width=\"[0-9pxt.]*\"")

I don't have commit permission to the code but this change is trivial, so I'm not offering to send a diff or any such. But will help is anyone wnat me to.

David

[davo]

Hmm, sorry, that should have been "line 22" not 23. Forgot I'd added a debugging line further up. So currently it says -

file(STRINGS  ${IMAGE_INPUT} NEW_SCALE_LINE REGEX "[^-]width=\"[0-9pxt.]*\"")

But it needs to say -

file(STRINGS  ${IMAGE_INPUT} NEW_SCALE_LINE LIMIT_COUNT 1 REGEX "[^-]width=\"[0-9pxt.]*\"")

and will install without fatal errors !

If I can help with anything, more than happy .....

David

[kazer]

Thanks for your report and patch. I cannot reproduce the issue with the current code.

Museum : ​https://circle-artifacts.com/gh/navit-gps/navit/853/artifacts/0/tmp/circle-artifacts.5GUwwNH/xpm/museum.svg Hotel : ​https://circle-artifacts.com/gh/navit-gps/navit/853/artifacts/0/tmp/circle-artifacts.5GUwwNH/xpm/hotel.svg

Are you guys still facing this problem? Maybe this is related to the tool used for the conversion.

I tested in my own dev environment and the CI.

[tobe deprez]

Also here, the new code seems to build without problems

[kazer]

Ok, we can close the ticket then.

Thanks!