From dde8765a49228ef0b1529341b92474782a5a1553 Mon Sep 17 00:00:00 2001
From: Rosen Penev <rosenp@gmail.com>
Date: Fri, 10 Feb 2023 17:03:34 -0800
Subject: [PATCH] don't assign in while

Fixes MSVC's warning C4706: assignment within conditional expression

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 src/basicio.cpp  | 10 ++++++----
 src/jpgimage.cpp |  5 +++--
 src/pgfimage.cpp |  5 +++--
 src/psdimage.cpp |  5 +++--
 4 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/basicio.cpp b/src/basicio.cpp
index 373d7c9c..b2655fac 100644
--- a/src/basicio.cpp
+++ b/src/basicio.cpp
@@ -321,9 +321,9 @@ size_t FileIo::write(BasicIo& src) {
     return 0;
 
   byte buf[4096];
-  size_t readCount = 0;
   size_t writeTotal = 0;
-  while ((readCount = src.read(buf, sizeof(buf)))) {
+  size_t readCount = src.read(buf, sizeof(buf));
+  while (readCount != 0) {
     size_t writeCount = std::fwrite(buf, 1, readCount, p_->fp_);
     writeTotal += writeCount;
     if (writeCount != readCount) {
@@ -331,6 +331,7 @@ size_t FileIo::write(BasicIo& src) {
       src.seek(writeCount - readCount, BasicIo::cur);
       break;
     }
+    readCount = src.read(buf, sizeof(buf));
   }
 
   return writeTotal;
@@ -746,11 +747,12 @@ size_t MemIo::write(BasicIo& src) {
     return 0;
 
   byte buf[4096];
-  size_t readCount = 0;
   size_t writeTotal = 0;
-  while ((readCount = src.read(buf, sizeof(buf)))) {
+  size_t readCount = src.read(buf, sizeof(buf));
+  while (readCount != 0) {
     write(buf, readCount);
     writeTotal += readCount;
+    readCount = src.read(buf, sizeof(buf));
   }
 
   return writeTotal;
diff --git a/src/jpgimage.cpp b/src/jpgimage.cpp
index 68214091..865a4716 100644
--- a/src/jpgimage.cpp
+++ b/src/jpgimage.cpp
@@ -914,10 +914,11 @@ void JpegBase::doWriteMetadata(BasicIo& outIo) {
     throw Error(ErrorCode::kerImageWriteFailed);
 
   DataBuf buf(4096);
-  size_t readSize = 0;
-  while ((readSize = io_->read(buf.data(), buf.size()))) {
+  size_t readSize = io_->read(buf.data(), buf.size());
+  while (readSize != 0) {
     if (outIo.write(buf.c_data(), readSize) != readSize)
       throw Error(ErrorCode::kerImageWriteFailed);
+    readSize = io_->read(buf.data(), buf.size());
   }
   if (outIo.error())
     throw Error(ErrorCode::kerImageWriteFailed);
diff --git a/src/pgfimage.cpp b/src/pgfimage.cpp
index 346b316d..01eaab5c 100644
--- a/src/pgfimage.cpp
+++ b/src/pgfimage.cpp
@@ -203,10 +203,11 @@ void PgfImage::doWriteMetadata(BasicIo& outIo) {
   // Copy the rest of PGF image data.
 
   DataBuf buf(4096);
-  size_t readSize = 0;
-  while ((readSize = io_->read(buf.data(), buf.size()))) {
+  size_t readSize = io_->read(buf.data(), buf.size());
+  while (readSize != 0) {
     if (outIo.write(buf.c_data(), readSize) != readSize)
       throw Error(ErrorCode::kerImageWriteFailed);
+    readSize = io_->read(buf.data(), buf.size());
   }
   if (outIo.error())
     throw Error(ErrorCode::kerImageWriteFailed);
diff --git a/src/psdimage.cpp b/src/psdimage.cpp
index a25f1c89..72e416b0 100644
--- a/src/psdimage.cpp
+++ b/src/psdimage.cpp
@@ -523,10 +523,11 @@ void PsdImage::doWriteMetadata(BasicIo& outIo) {
   io_->populateFakeData();
 
   // Copy remaining data
-  size_t readSize = 0;
-  while ((readSize = io_->read(lbuf.data(), lbuf.size()))) {
+  size_t readSize = io_->read(lbuf.data(), lbuf.size());
+  while (readSize != 0) {
     if (outIo.write(lbuf.c_data(), readSize) != readSize)
       throw Error(ErrorCode::kerImageWriteFailed);
+    readSize = io_->read(lbuf.data(), lbuf.size());
   }
   if (outIo.error())
     throw Error(ErrorCode::kerImageWriteFailed);