Fix SpotBugs warnings and tighten gates (#4418)

Author: shai-almog

.github/scripts/generate-quality-report.py

@@ -763,6 +763,7 @@ def main() -> None:
     if spotbugs:
         forbidden_rules = {
             "NP_ALWAYS_NULL",
+            "NP_NULL_PARAM_DEREF",
             "RCN_REDUNDANT_NULLCHECK_OF_NONNULL_VALUE",
             "RCN_REDUNDANT_NULLCHECK_OF_NULL_VALUE",
             "UWF_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR",
@@ -772,6 +773,7 @@ def main() -> None:
             "IA_AMBIGUOUS_INVOCATION_OF_INHERITED_OR_OUTER_METHOD",
             "LI_LAZY_INIT_STATIC",
             "RpC_REPEATED_CONDITIONAL_TEST",
+            "NS_NON_SHORT_CIRCUIT",
             "ES_COMPARING_PARAMETER_STRING_WITH_EQ",
             "FE_FLOATING_POINT_EQUALITY",
             "FE_TEST_IF_EQUAL_TO_NOT_A_NUMBER",
@@ -787,7 +789,9 @@ def main() -> None:
             "EQ_DOESNT_OVERRIDE_EQUALS",
             "CO_COMPARETO_INCORRECT_FLOATING",
             "DL_SYNCHRONIZATION_ON_SHARED_CONSTANT",
+            "SSD_DO_NOT_USE_INSTANCE_LOCK_ON_SHARED_STATIC_DATA",
             "DLS_DEAD_LOCAL_STORE",
+            "DLS_DEAD_LOCAL_STORE_OF_NULL",
             "DM_NUMBER_CTOR",
             "DMI_INVOKING_TOSTRING_ON_ARRAY",
             "EC_NULL_ARG",
@@ -819,6 +823,7 @@ def main() -> None:
             "NO_NOTIFY_NOT_NOTIFYALL",
             "NP_LOAD_OF_KNOWN_NULL_VALUE",
             "NP_BOOLEAN_RETURN_NULL",
+            "RC_REF_COMPARISON_BAD_PRACTICE_BOOLEAN",
             "REFLC_REFLECTION_MAY_INCREASE_ACCESSIBILITY_OF_CLASS",
             "REC_CATCH_EXCEPTION",
             "RCN_REDUNDANT_NULLCHECK_WOULD_HAVE_BEEN_A_NPE",

CodenameOne/src/com/codename1/facebook/FacebookRESTService.java

@@ -239,8 +239,11 @@ public void numericToken(double tok) {
     }
 
     public void keyValue(String key, String value) {
+        if (key == null) {
+            return;
+        }
         //make sure value is not null to prevent NPE
-        if (key != null && value == null) {
+        if (value == null) {
             value = "";
         }
         getCurrent().put(key, value);

CodenameOne/src/com/codename1/io/gzip/DeflaterOutputStream.java

@@ -84,7 +84,7 @@ public void write(int b) throws IOException {
     public void write(byte[] b, int off, int len) throws IOException {
         if (deflater.finished()) {
             throw new IOException("finished");
-        } else if (off < 0 | len < 0 | off + len > b.length) {
+        } else if (off < 0 || len < 0 || off + len > b.length) {
             throw new IndexOutOfBoundsException();
         } else if (len == 0) {
         } else {

CodenameOne/src/com/codename1/location/LocationManager.java

@@ -52,6 +52,7 @@ public abstract class LocationManager {
     public static final int OUT_OF_SERVICE = 1;
     public static final int TEMPORARILY_UNAVAILABLE = 2;
     private static LocationListener listener;
+    private static final Object LISTENER_LOCK = new Object();
     private LocationRequest request;
     private static Class backgroundlistener;
     private int status = TEMPORARILY_UNAVAILABLE;
@@ -198,7 +199,7 @@ protected LocationListener getLocationListener() {
      *          from getting updates
      */
     public void setLocationListener(final LocationListener l) {
-        synchronized (this) {
+        synchronized (LISTENER_LOCK) {
             if (listener != null) {
                 clearListener();
                 request = null;
@@ -243,7 +244,7 @@ protected Class getBackgroundLocationListener() {
      *                         try to create an instance and invoke the locationUpdated method
      */
     public void setBackgroundLocationListener(Class locationListener) {
-        synchronized (this) {
+        synchronized (LISTENER_LOCK) {
             if (backgroundlistener != null) {
                 clearBackgroundListener();
             }

CodenameOne/src/com/codename1/properties/InstantUI.java

@@ -81,7 +81,7 @@ public void excludeProperties(PropertyBase... exclude) {
      * @return true if the property was excluded from the GUI
      */
     public boolean isExcludedProperty(PropertyBase exclude) {
-        return exclude.getClientProperty("cn1$excludeFromUI") == Boolean.TRUE;
+        return Boolean.TRUE.equals(exclude.getClientProperty("cn1$excludeFromUI"));
     }
 
     /**

CodenameOne/src/com/codename1/ui/BrowserComponent.java

@@ -1601,7 +1601,7 @@ public void putClientProperty(String key, Object value) {
      * @return true if debug mode was activated
      */
     public boolean isDebugMode() {
-        return getClientProperty("BrowserComponent.firebug") == Boolean.TRUE;
+        return Boolean.TRUE.equals(getClientProperty("BrowserComponent.firebug"));
     }
 
     /**

CodenameOne/src/com/codename1/ui/html/HTMLComponent.java

@@ -463,13 +463,13 @@ public HTMLComponent(DocumentRequestHandler handler) {
      * @param font    The actual Codename One font object
      */
     public static void addFont(String fontKey, Font font) {
-        if (fontKey != null) {
-            fontKey = fontKey.toLowerCase();
-        } else {
+        if (fontKey == null) {
             if (font.getCharset() != null) {
                 throw new IllegalArgumentException("Font key must be non-null for bitmap fonts");
             }
+            throw new IllegalArgumentException("Font key must be non-null");
         }
+        fontKey = fontKey.toLowerCase();
         fonts.put(fontKey, new HTMLFont(fontKey, font));
     }
 

CodenameOne/src/com/codename1/ui/plaf/UIManager.java

@@ -1901,7 +1901,6 @@ Style createStyle(String id, String prefix, boolean selected) {
                     style = new Style(getComponentStyle(baseStyle));
                 }
             } else {
-                baseStyle = null;
                 if (selected) {
                     style = new Style(defaultSelectedStyle);
                 } else {

CodenameOne/src/com/codename1/util/TBigInteger.java

@@ -1240,7 +1240,7 @@ public TBigInteger modPow(TBigInteger exponent, TBigInteger m) {
         }
         TBigInteger base = this;
 
-        if (m.isOne() | (exponent.sign > 0 & base.sign == 0)) {
+        if (m.isOne() || (exponent.sign > 0 && base.sign == 0)) {
             return TBigInteger.ZERO;
         }
         if (exponent.sign == 0) {