Issue 638 - Fresh commit on top of main to avoid what resulted in a m…

…essage rebase/merge on the original branch.

src/main/java/com/redhat/devtools/lsp4ij/features/completion/LSPCompletionContributor.java

@@ -10,17 +10,17 @@
  ******************************************************************************/
 package com.redhat.devtools.lsp4ij.features.completion;
 
-import com.intellij.codeInsight.completion.CompletionContributor;
-import com.intellij.codeInsight.completion.CompletionParameters;
-import com.intellij.codeInsight.completion.CompletionResultSet;
+import com.intellij.codeInsight.completion.*;
 import com.intellij.codeInsight.lookup.*;
 import com.intellij.codeInsight.lookup.impl.LookupImpl;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.progress.ProgressManager;
+import com.intellij.openapi.util.UserDataHolder;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiFile;
+import com.intellij.util.containers.ContainerUtil;
 import com.redhat.devtools.lsp4ij.LSPFileSupport;
 import com.redhat.devtools.lsp4ij.LSPIJUtils;
 import com.redhat.devtools.lsp4ij.LanguageServerItem;
@@ -35,9 +35,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
@@ -125,6 +123,7 @@ private void addCompletionItems(@NotNull CompletionParameters parameters,
         items.sort(completionProposalComparator);
         int size = items.size();
 
+        Set<String> addedLookupStrings = new HashSet<>();
         var completionFeature = languageServer.getClientFeatures().getCompletionFeature();
         LSPCompletionFeature.LSPCompletionContext context = new LSPCompletionFeature.LSPCompletionContext(parameters, languageServer);
         // Items now sorted by priority, low index == high priority
@@ -137,6 +136,51 @@ private void addCompletionItems(@NotNull CompletionParameters parameters,
             LookupElement lookupItem = completionFeature.createLookupElement(item, context);
             if (lookupItem != null) {
                 completionFeature.addLookupItem(context, completionPrefix, result, lookupItem, size - i, item);
+                ContainerUtil.addIfNotNull(addedLookupStrings, lookupItem.getLookupString());
+            }
+        }
+
+        // If completions were added from LSP and this is auto-completion or the explicit completion trigger was typed
+        // only once, add completions from other all other contributors except for the word completion contributor.
+        // Note that the word completion contributor only really kicks in when LSP completions are added in the context
+        // of a TextMate file (see TextMateCompletionContributor), but that's going to be very common for LSP usage
+        // since it's often adding (pseudo-)language support when not already present in the host JetBrains IDE.
+        if ((size > 0) && (parameters.getInvocationCount() < 2)) {
+            // Don't allow automatic execution of the remaining completion contributors; we'll execute them ourselves below
+            result.stopHere();
+
+            // Try to disable word completion by temporarily setting FORBID_WORD_COMPLETION=true on the completion process.
+            // Note that this will not work in some older IDE versions where WordCompletionContributor.addWordCompletionVariants()
+            // did not yet check the value of FORBID_WORD_COMPLETION
+            CompletionProcess completionProcess = parameters.getProcess();
+            UserDataHolder userDataHolder = completionProcess instanceof UserDataHolder ? (UserDataHolder) completionProcess : null;
+            boolean originalForbidWordCompletion = false;
+            if (userDataHolder != null) {
+                originalForbidWordCompletion = userDataHolder.getUserData(BaseCompletionService.FORBID_WORD_COMPLETION) == Boolean.TRUE;
+                userDataHolder.putUserData(BaseCompletionService.FORBID_WORD_COMPLETION, true);
+            }
+            try {
+                if (userDataHolder != null) {
+                    // If we disabled word completion, just run all remaining contributors
+                    result.runRemainingContributors(parameters, true);
+                } else {
+                    // If not, run all remaining contributors and only add results with distinct lookup strings
+                    result.runRemainingContributors(parameters, completionResult -> {
+                        LookupElement lookupElement = completionResult.getLookupElement();
+                        if (lookupElement != null) {
+                            String lookupString = lookupElement.getLookupString();
+                            if (!addedLookupStrings.contains(lookupString)) {
+                                result.consume(lookupElement);
+                                addedLookupStrings.add(lookupString);
+                            }
+                        }
+                    });
+                }
+            } finally {
+                // If appropriate, re-enable word completion
+                if (userDataHolder != null) {
+                    userDataHolder.putUserData(BaseCompletionService.FORBID_WORD_COMPLETION, originalForbidWordCompletion);
+                }
             }
         }
     }

src/main/resources/META-INF/plugin.xml

@@ -246,7 +246,7 @@
                 id="LSPCompletionContributor"
                 language="any"
                 implementationClass="com.redhat.devtools.lsp4ij.features.completion.LSPCompletionContributor"
-                order="first"/>
+                order="first, before wordCompletion"/>
 
         <!-- LSP textDocument/definition request support -->
         <gotoDeclarationHandler