8189092: ArrayIndexOutOfBoundsException on Linux in getCachedGlyph

[prrace]

I have added an evaluation in https://bugs.openjdk.java.net/browse/JDK-8207839
Please read that for more detail, but basically we are not properly preventing or
handling cases where fontconfig causes us to overflow the byte storage used
for a font "slot".

Progress

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Issue

JDK-8189092: ArrayIndexOutOfBoundsException on Linux in getCachedGlyph

Approvers

• Kevin Rushforth (kcr - Reviewer)

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[mlbridge]

Webrevs

• 00: Full (b6c1946)

[kevinrushforth]

Looks good to me. I don't think this needs a second review, although @bourgesl or @johanvos might want to weigh in.

[bourgesl]

I had a quick look by curiosity as it is not my field. Explanations really make sense, thanks Phil.
Bit masks & shifts look good and definitely it will make that code safer.
However I wonder how to deal with more than 255 fonts (1 byte limit) as it may happen on some systems, even not reallistic.
Thanks

[openjdk]

@prrace This change can now be integrated. The commit message will be:

8189092: ArrayIndexOutOfBoundsException on Linux in getCachedGlyph

Reviewed-by: kcr

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Since the source branch of this PR was last updated there have been 2 commits pushed to the master branch:

• ac71396: 8232929: Duplicate symbols when building static libraries
• ab6ea3b: 8232158: [macOS] Fallback to command line tools if xcode is missing

Since there are no conflicts, your changes will automatically be rebased on top of the above commits when integrating. If you prefer to do this manually, please merge master into your branch first.

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[prrace]

However I wonder how to deal with more than 255 fonts (1 byte limit) as it may happen on some systems, even not reallistic.

That would have to be > 255 fonts per fontconfig font, and we have additional filters
to eliminate fonts that don't add value (at least we do now with fixing the bug in that
code in fontpath_linux.c).
We could rework things to use 16 bit for font slot, although that would be a bigger change
and require more testing and really this is never going to be needed on Windows or Mac,
just some very small number of Linux systems that are not default configs ..

[prrace]

/integrate

[openjdk]

@prrace The following commits have been pushed to master since your change was applied:

• ac71396: 8232929: Duplicate symbols when building static libraries
• ab6ea3b: 8232158: [macOS] Fallback to command line tools if xcode is missing

Your commit was automatically rebased without conflicts.

Pushed as commit 5a70b0c.

[mlbridge]

Mailing list message from Phil Race prr@openjdk.org

Changeset: 5a70b0c
Author: Phil Race
Date: 2019-10-26 15:14:47 +0000
URL: https://git.openjdk.java.net/jfx/commit/5a70b0c5

8189092: ArrayIndexOutOfBoundsException on Linux in getCachedGlyph

Reviewed-by: kcr

! modules/javafx.graphics/src/main/java/com/sun/javafx/font/CompositeGlyphMapper.java
! modules/javafx.graphics/src/main/java/com/sun/prism/impl/GlyphCache.java
! modules/javafx.graphics/src/main/native-font/fontpath_linux.c