Merge pull request #19439 from nathawes/fix-line-col-conversion

[sourcekit] Fix line+column -> offset conversion when on the last line of a file with no terminating newline

Author: Nathan Hawes

lib/Basic/SourceLoc.cpp

@@ -320,11 +320,10 @@ llvm::Optional<unsigned> SourceManager::resolveFromLineCol(unsigned BufferId,
   const char *Ptr = InputBuf->getBufferStart();
   const char *End = InputBuf->getBufferEnd();
   const char *LineStart = Ptr;
-  for (; Ptr < End; ++Ptr) {
+  --Line;
+  for (; Line && (Ptr < End); ++Ptr) {
     if (*Ptr == '\n') {
       --Line;
-      if (Line == 0)
-        break;
       LineStart = Ptr+1;
     }
   }

test/SourceKit/Refactoring/semantic-refactoring/line-col-conversion.swift

@@ -0,0 +1,4 @@
+// RUN: %sourcekitd-test -req=local-rename -pos=4:7 -name new_name %s -- %s
+
+var Foo: Int {
+	var missingNewlineAtEndOfFile

tools/SourceKit/tools/sourcekitd-test/sourcekitd-test.cpp

@@ -1963,11 +1963,10 @@ static unsigned resolveFromLineCol(unsigned Line, unsigned Col,
   const char *Ptr = InputBuf->getBufferStart();
   const char *End = InputBuf->getBufferEnd();
   const char *LineStart = Ptr;
-  for (; Ptr < End; ++Ptr) {
+  --Line;
+  for (; Line && (Ptr < End); ++Ptr) {
     if (*Ptr == '\n') {
       --Line;
-      if (Line == 0)
-        break;
       LineStart = Ptr+1;
     }
   }