Re: Use convert -strip (issue 339350043 by address@hidden)

[bmwiedemann]

Reviewers: dulow kotic, lilypond-pkx, Dan Eble,

Message:
On 2018/06/02 19:29:16, Dan Eble wrote:

https://codereview.appspot.com/339350043/diff/1/Documentation/pictures/GNUmakefile
> File Documentation/pictures/GNUmakefile (right):


https://codereview.appspot.com/339350043/diff/1/Documentation/pictures/GNUmakefile#newcode29
> Documentation/pictures/GNUmakefile:29: convert -strip -depth 8
-geometry 50x50%
> $< $@
> It would be wise to add a brief comment before the dependency line
explaining
> why -strip is important, otherwise someone might come along later,
decide that
> it is pointless, and remove it.

> Are there any undesirable side effects of -strip, for example,
removing a
> copyright notice?  The man page says that -strip "strip[s the] image
of all
> profiles and comments" but I'm not familiar enough with convert to
know what
> that means.  Are profiles also unimportant here?

Not sure why the tools didnt show it, but this was handled in
https://sourceforge.net/p/testlilyissues/issues/5290/
and merged as commit d1d5f436a190929e38145cf8be7d4fa63b077b46

IMHO, git blame is usually a good tool to find out on why something was
added

and I don't think -strip removes important information in this case.

Description:
Use convert -strip

to not add timestamps to .png output files
to make build reproducible

See https://reproducible-builds.org/ for why this is good.

Without this patch, files in the openSUSE lilypond-doc package would
differ for every build:
/usr/share/doc/packages/lilypond/Documentation/pictures/baer-flat-bw.png
/usr/share/doc/packages/lilypond/Documentation/pictures/baer-flat-gray.png
/usr/share/doc/packages/lilypond/Documentation/pictures/henle-flat-bw.png
...

Please review this at https://codereview.appspot.com/339350043/

Affected files (+2, -2 lines):
  M Documentation/pictures/GNUmakefile


Index: Documentation/pictures/GNUmakefile
diff --git a/Documentation/pictures/GNUmakefile  
b/Documentation/pictures/GNUmakefile
index  
8f53363046bfa0ee0a161d9b2dfdfe8bdacd2120..2b5ae3796f5d781fc8cc323a81e4b98434ea9693  
100644
--- a/Documentation/pictures/GNUmakefile
+++ b/Documentation/pictures/GNUmakefile
@@ -26,10 +26,10 @@ endif
 ### Rules

 $(outdir)/%-flat-gray.png: %-flat-gray.png
-       convert -depth 8 -geometry 50x50% $< $@
+       convert -strip -depth 8 -geometry 50x50% $< $@

 $(outdir)/%-flat-bw.png: %-flat-bw.png
-       convert -depth 8 -geometry 50x50% $< $@
+       convert -strip -depth 8 -geometry 50x50% $< $@

 $(outdir)/%.png: $(top-src-dir)/Documentation/pictures/%.png
        $(LN_SRC_TO_BUILD) -f $< $@