Refactor InternalReadLine to not unroll Size == 0 case

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index aa5831f583501e3711cf64b2962e57692549fc60..99db66f03c50219a23e09da7981ae2cc586bec1a 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -970,13 +970,12 @@ public:
    {
       if (unlikely(Size == 0))
         return nullptr;
+      // Read one byte less than buffer size to have space for trailing 0.
       --Size;
-      To[0] = '\0';
-      if (unlikely(Size == 0))
-        return To;
+
       char * const InitialTo = To;
 
-      do {
+      while (Size > 0) {
         if (buffer.empty() == true)
         {
            buffer.reset();
@@ -1004,7 +1003,7 @@ public:
         Size -= actualread;
         if (newline != nullptr)
            break;
-      } while (Size > 0);
+      }
       *To = '\0';
       return InitialTo;
    }