Inkscape

Bug #1425387
Comment #5

Comment 5 for bug 1425387

Revision history for this message

David Mathog (mathog) wrote on 2015-02-26:

That a bug fix in this region of code caused a regression does not surprise me. The Inkscape code which was modified is a layer above Pango and this code is making assumptions about how languages behave - without knowing what language it is dealing with and which rules actually apply for that language. So that fixing a Telugu problem breaks Thai is not at all surprising. [This whole section of code should be thrown in the dust bin and replaced with, for instance, the equivalent section from LibreOffice, where there are more developers working in more languages. That would be a huge job, of course.]

Anyway, I took a quick look at it and see that I do not have enough information to understand what the actual problem is. I will at least need the following to have any chance of figuring it out:

1. Does this only happen with the Norasi font or does it also occur with other Thai fonts?

2. Is the issue only when you type text in on Inkscape, or is it a matter of the unicode string no matter where it comes from? For instance, could you cut that text from another application and paste it into Inkscape and have it look as it should?

3. ~suv's example shows that the fonts are on different characters in the drawing surface and the Text and Font.. display.
Which one is correct?

4. I opened drawing.svg on r13915 on Windows XP and it used "Norasi" font and it didn't look like either one of your examples. It does look like one pane in the one ~suv posted. See attachment. Since I have no idea what any of the
symbols mean I cannot work with that amount of variation. (Opening it in Firefox didn't help, it was a mess in there.) Please provide an SVG with a much longer section of Thai text. Something that uses all the consonants and vowels, if that is possible. If it will not fit on one line make them separate text boxes. Please put a couple of extra spaces between words, and provide a picture of what this should look like.

5. Are you aware of anything unusual, with respect to Unicode properties of the vowel in question, or the Thai language in general? Is the language L->R or R->L? Does it have any unusual grouping properties? Does it have modifiers that change the shape of base glyphs other than by placing a vowel marking on or near a base consonant?

6. Is it just that one vowel that causes this issue, or all vowels?

That a bug fix in this region of code caused a regression does not surprise me.  The Inkscape code which was modified is a layer above Pango and this code is making assumptions about how languages behave - without knowing what language it is dealing with and which rules actually apply for that language.   So that fixing a Telugu problem breaks Thai is not at all surprising.  [This whole section of code should be thrown in the dust bin and replaced with, for instance, the equivalent section from LibreOffice, where there are more developers working in more languages.  That would be a huge job, of course.]

Anyway, I took a quick look at it and see that I do not have enough information to understand what the actual problem is.  I will at least need the following to have any chance of figuring it out:

1.  Does this only happen with the Norasi font or does it also occur with other Thai fonts?

2.  Is the issue only when you type text in on Inkscape, or is it a matter of the unicode string no matter where it comes from?   For instance, could you cut that text from another application and paste it into Inkscape and have it look as it should?

3.  ~suv's example shows that the fonts are on different characters in the drawing surface and the Text and Font.. display.
Which one is correct?

4.  I opened drawing.svg on r13915 on Windows XP and it used "Norasi" font and it didn't look like either one of your examples.  It does look like one pane in the one ~suv posted.  See attachment.    Since I have no idea what any of the
symbols mean I cannot work with that amount of variation.  (Opening it in Firefox didn't help, it was a mess in there.)  Please provide an SVG with a much longer section of Thai text.  Something that uses all the consonants and vowels, if that is possible.  If it will not fit on one line make them separate text boxes.  Please put a couple of extra spaces between words, and provide a picture of what this should look like.

5.  Are you aware of anything unusual, with respect to Unicode properties of the vowel in question, or the Thai language in general?   Is the language L->R or R->L?  Does it have any unusual grouping properties?   Does it have modifiers that change the shape of base glyphs other than by placing a vowel marking on or near a base consonant?

6.  Is it just that one vowel that causes this issue, or all vowels?