Document rationale for gtk-update-icon-cache being in posttrans

- Document rationale for gtk-update-icon-cache being in posttrans
- Remove extra spaces in posttrans files section headers
- Resolves: RHEL-71488

java-21-openjdk.spec

@@ -366,7 +366,7 @@
 %global top_level_dir_name   %{vcstag}
 %global top_level_dir_name_backup %{top_level_dir_name}-backup
 %global buildver        11
-%global rpmrelease      4
+%global rpmrelease      5
 # Settings used by the portable build
 %global portablerelease 1
 # Portable suffix differs between RHEL and CentOS
@@ -563,6 +563,19 @@ then
 fi
 }
 
+# Invoke gtk-update-icon-cache in posttrans instead of post as an
+# optimization.  If other packages in the transaction install icons
+# and use this optimization, then invocations of gtk-update-icon-cache
+# will all happen in succession, and invocations after the first one
+# will notice that the cache is fresh and immediately succeed.  If
+# this were instead done in each package's post, then the icon cache
+# would be regenerated every time, rendering the whole transaction
+# slower.
+# See:
+# https://lists.fedoraproject.org/archives/list/packaging\
+# @lists.fedoraproject.org/thread/HXIIKIHBMT3HELPKWH2BAXRNIF7BPPJD/
+# and:
+# https://fedoraproject.org/wiki/Archive:PackagingDrafts/Icon_Cache
 %define posttrans_script() %{expand:
 %{update_desktop_icons}
 }
@@ -2212,7 +2225,7 @@ exit 0
 %{postun_devel %{nil}}
 exit 0
 
-%posttrans  devel
+%posttrans devel
 %{posttrans_devel %{nil}}
 exit 0
 
@@ -2274,7 +2287,7 @@ exit 0
 %{postun_devel -- %{debug_suffix_unquoted}}
 exit 0
 
-%posttrans  devel-slowdebug
+%posttrans devel-slowdebug
 %{posttrans_devel -- %{debug_suffix_unquoted}}
 exit 0
 %endif
@@ -2312,7 +2325,7 @@ exit 0
 %{postun_devel -- %{fastdebug_suffix_unquoted}}
 exit 0
 
-%posttrans  devel-fastdebug
+%posttrans devel-fastdebug
 %{posttrans_devel -- %{fastdebug_suffix_unquoted}}
 exit 0
 %endif
@@ -2409,6 +2422,11 @@ exit 0
 %endif
 
 %changelog
+* Thu Jan 23 2025 Thomas Fitzsimmons <fitzsim@redhat.com> - 1:21.0.5.0.11-5
+- Document rationale for gtk-update-icon-cache being in posttrans
+- Remove extra spaces in posttrans files section headers
+- Resolves: RHEL-71488
+
 * Tue Dec 17 2024 Thomas Fitzsimmons <fitzsim@redhat.com> - 1:21.0.5.0.11-4
 - Revert incorrect automated Release change from 1:21.0.5.0.11-2.1
 - Set rpmrelease to 4