[clang-tools-extra] 3346cec - [clangd] Fix write past end pointer

[Kadir Cetinkaya via cfe-commits]

Author: Kadir Cetinkaya
Date: 2019-12-19T21:50:32+01:00
New Revision: 3346cecd4c0c960377b441606b6382a684daf061

URL: https://github.com/llvm/llvm-project/commit/3346cecd4c0c960377b441606b6382a684daf061
DIFF: https://github.com/llvm/llvm-project/commit/3346cecd4c0c960377b441606b6382a684daf061.diff

LOG: [clangd] Fix write past end pointer

Added: 
    

Modified: 
    clang-tools-extra/clangd/FormattedString.cpp

Removed: 
    


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diff  --git a/clang-tools-extra/clangd/FormattedString.cpp b/clang-tools-extra/clangd/FormattedString.cpp
index 5c225139de23..a7a63a476c3c 100644
--- a/clang-tools-extra/clangd/FormattedString.cpp
+++ b/clang-tools-extra/clangd/FormattedString.cpp
@@ -104,13 +104,12 @@ std::string canonicalizeSpaces(std::string Input) {
     return "";
   // Go over each word and add it to the string.
   for (llvm::StringRef Word : Words) {
+    if (WritePtr > Input.begin())
+      *WritePtr++ = ' '; // Separate from previous block.
     llvm::for_each(Word, [&WritePtr](const char C) { *WritePtr++ = C; });
-    // Separate from next block.
-    *WritePtr++ = ' ';
   }
-  // Get rid of extra spaces, -1 is for the trailing space introduced with last
-  // word.
-  Input.resize(WritePtr - Input.begin() - 1);
+  // Get rid of extra spaces.
+  Input.resize(WritePtr - Input.begin());
   return Input;
 }