sdbus++-gen-meson: fix [more] meson dependencies

As a follow on to 5800d07910384ffad8409515bc510812e4f34334,
additional cases were noticed where the meson dependencies are
not correctly updated when multiple YAML files are used (such
as interfaces and events).

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie47bc156c2b3954d3c47c9d07a2e106d7cc87c63
diff --git a/example/gen/meson.build b/example/gen/meson.build
index c63d829..38522c5 100644
--- a/example/gen/meson.build
+++ b/example/gen/meson.build
@@ -5,10 +5,10 @@
     check: true,
 ).stdout().strip().split('\n')[0]
 
-if sdbuspp_gen_meson_ver != 'sdbus++-gen-meson version 8'
+if sdbuspp_gen_meson_ver != 'sdbus++-gen-meson version 9'
     warning('Generated meson files from wrong version of sdbus++-gen-meson.')
     warning(
-        'Expected "sdbus++-gen-meson version 8", got:',
+        'Expected "sdbus++-gen-meson version 9", got:',
         sdbuspp_gen_meson_ver
     )
 endif
diff --git a/example/gen/net/poettering/Calculator/meson.build b/example/gen/net/poettering/Calculator/meson.build
index 455afe9..1b4cc9b 100644
--- a/example/gen/net/poettering/Calculator/meson.build
+++ b/example/gen/net/poettering/Calculator/meson.build
@@ -1,7 +1,7 @@
 # Generated file; do not modify.
 generated_sources += custom_target(
     'net/poettering/Calculator__cpp'.underscorify(),
-    input: [ '../../../../yaml/net/poettering/Calculator.interface.yaml',  ],
+    input: [ '../../../../yaml/net/poettering/Calculator.events.yaml', '../../../../yaml/net/poettering/Calculator.interface.yaml',  ],
     output: [ 'event.cpp', 'event.hpp', 'common.hpp', 'server.cpp', 'server.hpp', 'aserver.hpp', 'client.hpp',  ],
     depend_files: sdbusplusplus_depfiles,
     command: [
diff --git a/test/gen/meson.build b/test/gen/meson.build
index c63d829..38522c5 100644
--- a/test/gen/meson.build
+++ b/test/gen/meson.build
@@ -5,10 +5,10 @@
     check: true,
 ).stdout().strip().split('\n')[0]
 
-if sdbuspp_gen_meson_ver != 'sdbus++-gen-meson version 8'
+if sdbuspp_gen_meson_ver != 'sdbus++-gen-meson version 9'
     warning('Generated meson files from wrong version of sdbus++-gen-meson.')
     warning(
-        'Expected "sdbus++-gen-meson version 8", got:',
+        'Expected "sdbus++-gen-meson version 9", got:',
         sdbuspp_gen_meson_ver
     )
 endif
diff --git a/tools/sdbus++-gen-meson b/tools/sdbus++-gen-meson
index 1807108..5b61382 100755
--- a/tools/sdbus++-gen-meson
+++ b/tools/sdbus++-gen-meson
@@ -36,7 +36,7 @@
 ## if a repository contains old copies of the generated meson.build files and
 ## needs an update.  We should increment the version number whenever the
 ## resulting meson.build would change.
-tool_version="sdbus++-gen-meson version 8"
+tool_version="sdbus++-gen-meson version 9"
 function show_version() {
     echo "${tool_version}"
 }
@@ -180,7 +180,7 @@
     sources=""
     outputs=""
     for s in ${interfaces[$1]}; do
-        sources="'${yamldir}/$1.${s}', "
+        sources="${sources}'${yamldir}/$1.${s}', "
 
         case "${s}" in
             errors.yaml)