pic2graph: Adapt to old convert(1) programs.

	* contrib/pic2graph/pic2graph.sh: Grep convert's -help output
	  for the string "-trim".  If it is not found, the old method
	  for image trimming documented in pic2graph's man page, "-crop
	  0x0", is used.  I am motivated by the fact that the warning
	  about this in our man page is very old (10 years or more), and
	  I wanted to get rid of it.

	  pic2graph emits a warning when performing this fallback, in
	  the event the ImageMagick and/or GraphicsMagick teams surprise
	  the world again.

	* contrib/pic2graph/pic2graph.1.man: Remove BUGS section, the
	  entire contents of which was dedicated to convert's change in
	  behavior.

NEWS:
* Add Emacs fill-column.
* Add Vim modeline.
* Wrap the few lines in this file that were longer that 76 columns
  (about 6 out of almost 2,900) and reflow their paragraphs.

Signed-off-by: G. Branden Robinson <g.branden.robinson@gmail.com>

2 files changed, 12 insertions, 27 deletions

diff --git a/contrib/pic2graph/pic2graph.1.man b/contrib/pic2graph/pic2graph.1.man
index 42f5ecc62..b9ea5c3a8 100644
--- a/contrib/pic2graph/pic2graph.1.man
+++ b/contrib/pic2graph/pic2graph.1.man
@@ -177,32 +177,6 @@ Otherwise, temporary files will be created in
 .
 .
 .\" ====================================================================
-.SH BUGS
-.\" ====================================================================
-.
-Due to changes in the behavior of ImageMagick
-.BR \%convert (1)
-that are both forward and backward-incompatible,
-mismatches between your
-.B pic2graph
-and
-.BR \%convert (1)
-versions may produce zero-sized or untrimmed output images.
-.
-For this version of
-.B pic2graph
-you will need a version of
-.BR \%convert (1)
-that supports the
-.B \-trim
-option; older versions of
-.B pic2graph
-used
-.BR \-crop\~0x0 ,
-which no longer has trimming behavior.
-.
-.
-.\" ====================================================================
 .SH AUTHORS
 .\" ====================================================================
 .B pic2graph
diff --git a/contrib/pic2graph/pic2graph.sh b/contrib/pic2graph/pic2graph.sh
index fd3c4c998..7773b2675 100644
--- a/contrib/pic2graph/pic2graph.sh
+++ b/contrib/pic2graph/pic2graph.sh
@@ -34,6 +34,7 @@
 #
 groffpic_opts=""
 convert_opts=""
+convert_trim_arg="-trim"
 format="png"
 eqndelim='$$'
 
@@ -83,6 +84,15 @@ if test -z "$tmp"; then
     { (exit 1); exit 1; }
 fi
 
+# See if the installed version of convert(1) is new enough to support the -trim
+# option.  Versions that didn't were described as "old" as early as 2008.
+is_convert_recent=`convert -help | grep -e -trim`
+if test -z "$is_convert_recent"
+then
+    echo "$0: warning: falling back to old '-crop 0x0' trim method" >&2
+    convert_trim_arg="-crop 0x0"
+fi
+
 trap 'exit_status=$?; rm -rf $tmp && exit $exit_status' EXIT INT TERM
 
 # Here goes:
@@ -92,7 +102,8 @@ trap 'exit_status=$?; rm -rf $tmp && exit $exit_status' EXIT INT TERM
 # 4. Use convert(1) to crop the PostScript and turn it into a bitmap.
 (echo ".EQ"; echo $eqndelim; echo ".EN"; echo ".PS"; cat; echo ".PE") | \
     groff -e -p $groffpic_opts -Tps -P-pletter > $tmp/pic2graph.ps \
-    && convert -trim $convert_opts $tmp/pic2graph.ps $tmp/pic2graph.$format \
+    && convert $convert_trim_arg $convert_opts $tmp/pic2graph.ps \
+       $tmp/pic2graph.$format \
     && cat $tmp/pic2graph.$format
 
 # End