include current git commit hash in about dialog

build.gradle

@@ -18,6 +18,15 @@ if(System.getProperty("os.arch") == "aarch64") {
     targetName = "-" + osArch
 }
 
+def getCommitHash = { ->
+    def stdout = new ByteArrayOutputStream()
+    exec {
+        commandLine 'git', 'rev-parse', '--short', 'HEAD'
+        standardOutput = stdout
+    }
+    return stdout.toString().trim()
+}
+
 group "com.sparrowwallet"
 version "${sparrowVersion}"
 
@@ -127,6 +136,11 @@ processResources {
             exclude "${osName}/${osArch}/**"
         }
     }
+    filesMatching('**/about.fxml') {
+        filter { line ->
+            line.replace('<!--COMMIT_HASH-->', "<Label text=\"Commit Hash: ${getCommitHash()}\" styleClass=\"commit-hash\"/>")
+        }
+    }
 }
 
 test {

src/main/resources/com/sparrowwallet/sparrow/about.css

@@ -13,3 +13,7 @@
     -fx-padding: 10 25 25 25;
 }
 
+.commit-hash {
+    -fx-opacity: 0.3;
+}
+

src/main/resources/com/sparrowwallet/sparrow/about.fxml

@@ -26,6 +26,8 @@
             <HBox><Label text="If you find Sparrow useful, consider donating at "/><Hyperlink text="https://sparrowwallet.com/donate" onAction="#openDonate"/></HBox>
         </VBox>
         <HBox styleClass="button-area" alignment="BOTTOM_RIGHT" VBox.vgrow="SOMETIMES">
+            <!--COMMIT_HASH-->
+            <Region HBox.hgrow="ALWAYS" />
             <Button text="Close" onAction="#close" />
         </HBox>
     </VBox>