Actually verify when dependency and main project is open

Author: sheetalkamat

src/compiler/sourcemap.ts

@@ -583,7 +583,8 @@ namespace ts {
     }
 
     function compareSourcePositions(left: SourceMappedPosition, right: SourceMappedPosition) {
-        return compareValues(left.sourceIndex, right.sourceIndex);
+        Debug.assert(left.sourceIndex === right.sourceIndex);
+        return compareValues(left.sourcePosition, right.sourcePosition);
     }
 
     function compareGeneratedPositions(left: MappedPosition, right: MappedPosition) {

src/server/editorServices.ts

@@ -2604,7 +2604,7 @@ namespace ts.server {
 
         /** @internal */
         fileExists(fileName: NormalizedPath): boolean {
-            return this.filenameToScriptInfo.has(fileName) || this.host.fileExists(fileName);
+            return !!this.getScriptInfoForNormalizedPath(fileName) || this.host.fileExists(fileName);
         }
 
         private findExternalProjectContainingOpenScriptInfo(info: ScriptInfo): ExternalProject | undefined {

src/server/project.ts

@@ -759,7 +759,10 @@ namespace ts.server {
         }
 
         containsScriptInfo(info: ScriptInfo): boolean {
-            return this.isRoot(info) || (!!this.program && this.program.getSourceFileByPath(info.path) !== undefined);
+            if (this.isRoot(info)) return true;
+            if (!this.program) return false;
+            const file = this.program.getSourceFileByPath(info.path);
+            return !!file && file.resolvedPath === info.path;
         }
 
         containsFile(filename: NormalizedPath, requireOpen?: boolean): boolean {