1 Updating libpng in OpenJDK

     2 

     3 1) Update the src/java.desktop/share/legal/libpng.md file.

     4 Usually this is just a matter of updating the version at the top,

     5 and in the embedded text, and extending the copyright date.

     6 

     7 The updated info comes from the LICENSE file.

     8 

     9 2) Copy LICENSE, README, and CHANGES from the new version into OpenJDK's

    10 libpng source directory

    11 

    12 3) OpenJDK includes just a subset of the files, since we use it only for reading.

    13 Copy only the same .c and .h files as are already there and re-apply the

    14 GPL v2 + CP header to all the updated files. These files also have a special

    15 note referencing the previous license. Restore everything as it was.

    16 You can either do this with a clever-enough script, or manually copy/paste.

    17 There are 18 files to update so either is do-able.

    18 

    19 4) Special and careful handling of pnglibconf.h

    20 OpenJDK has a heavily modified copy of pnglibconf.h.

    21 This is the trickiest part of the whole exercise.

    22 This file is generated by png at build time.

    23 Except for the dates and version, you should generally not need to update

    24 OpenJDK's copy unless the new version of PNG has added rquired new #defines

    25 that cause problems building.

    26 You can run configure && make on the downloaded source and compare but we

    27 do not want to enable any of the WRITE support, and there are many more

    28 modifications as well.

    29 So do NOT just copy in a file from the new libpng.

    30 The header may be the only thing you want to update.

    31 Also this file has a special "THIS FILE WAS MODIFIED BY ORACLE, INC."

    32 line in the GPL header.

    33 So lots of reasons to not copy over the new version,

    34 and instead just tweak the existing one.

    35 

    36 5) Run scripts to expand tabs and remove trailing white space from source files.

    37 

    38 Use expand to remove tabs

    39 expand ${f} > ${f}.tmp

    40 mv ${f}.tmp $f

    41 

    42 Use sed to remove trailing white space

    43 sed -e 's/[ ]* $//' ${f} > ${f}.tmp

    44 mv ${f}.tmp $f

    45 

    46 6) As with all native code, run it through the official build systems, in case

    47 the updated code trigger any fatal warnings with the official compilers.

    48 

    49 7) Run the splashscreen jtreg tests.