mega-melt: update to realign with melting-pot.sh

The melting-pot.sh script in scijava-scripts now places version property
pins into a dedicated version-pins.xml file in Maven settings.xml style,
rather than passing the versions directly to mvn via -D arguments.
So we need to adjust the post-generation hacks here accordingly.

And ensure that sed commands really do something.
Whether or not sed changes any lines, it returns success.
But we want to be sure that the command actually made a change.

tests/run.sh

@@ -6,6 +6,8 @@
 
 die () { echo "$*" >&2; exit 1; }
 
+changed () { ! diff $@ >/dev/null; }
+
 sectionStart() {
   startTime=$(date +%s)
   echo
@@ -117,6 +119,7 @@ test "$(grep -F "[ERROR]" "$meltingPotLog" | grep -v "using default branch")" &&
   die 'Melting pot generation failed!'
 
 buildScript="$meltingPotDir/build.sh"
+versionPins="$meltingPotDir/version-pins.xml"
 
 echo
 echo 'Hacking in any changed components...'
@@ -196,7 +199,7 @@ do
   if [ -f gav ]
   then
     mv gav gav.prehacks
-    sed -E "s;:[^:]*$;:999;" gav.prehacks > gav || {
+    sed -E "s;:[^:]*$;:999;" gav.prehacks > gav && changed gav.prehacks gav || {
       touch "$failFile"
       die "$g:$a: failed to adjust gav version"
     }
@@ -210,17 +213,20 @@ do
   }
   printf .
 
-  # Adjust component version to 999 in melting pot's build.sh.
+  # Adjust component version to 999 in melting pot's version-pins.xml.
   cd "$meltingPotDir"
-  test -f "$buildScript.prehacks" || cp "$buildScript" "$buildScript.prehacks" || {
+  test -f "$versionPins.prehacks" || cp "$versionPins" "$versionPins.prehacks" || {
     touch "$failFile"
-    die "$g:$a: failed to back up $buildScript"
+    die "$g:$a: failed to back up $versionPins"
   }
   printf .
-  mv -f "$buildScript" "$buildScript.tmp" &&
-  sed -E "s;(-D($g\\.)?$a\\.version)=[^ ]*;\1=999;g" "$buildScript.tmp" > "$buildScript" || {
+  echo "$a" | grep -q '^[0-9]' && aa="_$a" || aa="$a"
+  mv -f "$versionPins" "$versionPins.tmp" &&
+    sed -E "s;<\($g\\.$a\|$aa\)\\.version>[^<]*;<\1.version>999;g" "$versionPins.tmp" > "$versionPins" &&
+    changed "$versionPins.tmp" "$versionPins" ||
+  {
     touch "$failFile"
-    die "$g:$a: failed to adjust component version in $buildScript"
+    die "$g:$a: failed to adjust component version in $versionPins"
   }
   printf .
 
@@ -235,36 +241,48 @@ do
   }
   printf ".\n"
 done
-rm -f "$buildScript.tmp" "$meltScript.tmp"
+rm -f "$versionPins.tmp" "$meltScript.tmp"
 test ! -f "$failFile" ||
   die "Failed to hack in changed components!"
 
-sectionStart 'Adjusting the melting pot: build.sh script'
+sectionStart 'Adjusting the melting pot: version-pins.xml configuration'
 
-cp "$buildScript" "$buildScript.original" &&
+cp "$versionPins" "$versionPins.original" &&
 
 # HACK: Remove known-duplicate short version properties, keeping
 # the short version declaration only for the more common groupId.
 # E.g.: org.antlr:antlr is preferred over antlr:antlr, so we set
 # antlr.version to match org.antlr:antlr, not antlr:antlr.
-mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E 's;(-D('"$shortVersionClashes"').version=[^ ]*) -D[^ ]*;\1;' "$buildScript.tmp" > "$buildScript" &&
-
-# HACK: Add leading underscore to version properties that start with a digit.
-mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E 's; -D([0-9][^ ]*);& -D_\1;' "$buildScript.tmp" > "$buildScript" &&
+mv -f "$versionPins" "$versionPins.tmp" &&
+sed -E 's;(<('"$shortVersionClashes"')\.version>[^ ]*) <[^ ]*;\1;' "$versionPins.tmp" > "$versionPins" &&
+  changed "$versionPins.tmp" "$versionPins" ||
+  die 'Error adjusting melting pot version pins! [1]'
 
 # HACK: Add non-standard version properties used prior to
 # pom-scijava 32.0.0-beta-1; see d0bf752070d96a2613c42e4e1ab86ebdd07c29ee.
-mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E 's; -Dsc.fiji.3D_Blob_Segmentation\.version=([^ ]*);& -DFiji_3D_Blob_Segmentation.version=\1;' "$buildScript.tmp" > "$buildScript" &&
-mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E 's; -Dsc.fiji.(3D_Objects_Counter|3D_Viewer)\.version=([^ ]*);& -DImageJ_\1.version=\2;' "$buildScript.tmp" > "$buildScript" &&
+mv -f "$versionPins" "$versionPins.tmp" &&
+sed -E 's; <sc.fiji.3D_Blob_Segmentation\.version>([^<]*)</sc.fiji.3D_Blob_Segmentation.version>;& <Fiji_3D_Blob_Segmentation.version>\1</Fiji_3D_Blob_Segmentation.version>;' "$versionPins.tmp" > "$versionPins" &&
+  changed "$versionPins.tmp" "$versionPins" &&
+mv -f "$versionPins" "$versionPins.tmp" &&
+sed -E 's; <sc.fiji.(3D_Objects_Counter|3D_Viewer)\.version>([^<]*)</sc.fiji.(3D_Objects_Counter|3D_Viewer).version>;& <ImageJ_\1.version>\2</ImageJ_\1.version>;' "$versionPins.tmp" > "$versionPins" &&
+  changed "$versionPins.tmp" "$versionPins" ||
+  die 'Error adjusting melting pot version pins! [2]'
 
 # HACK: Add non-standard net.imagej:ij version property used prior to
 # pom-scijava 28.0.0; see 7d2cc442b107b3ac2dcb799d282f2c0b5822649d.
-mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E 's; -Dij\.version=([^ ]*);& -Dimagej1.version=\1;' "$buildScript.tmp" > "$buildScript" &&
+mv -f "$versionPins" "$versionPins.tmp" &&
+sed -E 's; <ij\.version>([^<]*)</ij\.version>;& <imagej1.version>\1</imagej1.version>;' "$versionPins.tmp" > "$versionPins" &&
+  changed "$versionPins.tmp" "$versionPins" ||
+  die 'Error adjusting melting pot version pins! [3]'
+
+rm "$versionPins.tmp" ||
+  die 'Error adjusting melting pot version pins! [4]'
+
+sectionEnd # Adjusting the melting pot: version-pins.xml configuration
+
+sectionStart 'Adjusting the melting pot: build.sh script'
+
+cp "$buildScript" "$buildScript.original" &&
 
 # HACK: Add explicit kotlin.version to match our pom-scijava-base.
 # Otherwise, components built on older pom-scijava-base will have
@@ -294,7 +312,8 @@ enforcerVersion=$(
   -Dexec.args='${maven-enforcer-plugin.version}' --non-recursive validate exec:exec 2>&1 |
   head -n1 | sed 's;\(.\[[0-9]m\)*;;') &&
 mv -f "$buildScript" "$buildScript.tmp" &&
-sed -E "s;mvn -Denforcer.skip;& -Dmaven-enforcer-plugin.version=$enforcerVersion -Dkotlin.version=$kotlinVersion;" "$buildScript.tmp" > "$buildScript" &&
+sed -E "s;mvn .*-Denforcer.skip;& -Dmaven-enforcer-plugin.version=$enforcerVersion -Dkotlin.version=$kotlinVersion;" "$buildScript.tmp" > "$buildScript" &&
+  changed "$buildScript.tmp" "$buildScript" &&
 
 chmod +x "$buildScript" &&
 rm "$buildScript.tmp" ||