coverity fixes

Signed-off-by: Rosen Penev <rosenp@gmail.com>

samples/geotag.cpp

@@ -420,13 +420,6 @@ std::string makePath(const std::string& dir, const std::string& file) {
   return dir + std::string(EXV_SEPARATOR_STR) + file;
 }
 
-const char* makePath(const char* dir, const char* file) {
-  static char result[_MAX_PATH];
-  std::string r = makePath(std::string(dir), std::string(file));
-  strcpy(result, r.c_str());
-  return result;
-}
-
 // file utilities
 bool readDir(const char* path, Options& options) {
   bool bResult = false;
@@ -452,7 +445,7 @@ bool readDir(const char* path, Options& options) {
         if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
           // _tprintf(TEXT("  %s   <DIR>\n"), ffd.cFileName);
         } else {
-          std::string pathName = makePath(path, std::string(ffd.cFileName));
+          std::string pathName = makePath(path, ffd.cFileName);
           if (getFileType(pathName, options) == typeImage) {
             gFiles.push_back(pathName);
           }

src/basicio.cpp

@@ -167,10 +167,7 @@ int FileIo::Impl::switchMode(OpMode opMode) {
   if (offset == -1)
     return -1;
   // 'Manual' open("r+b") to avoid munmap()
-  if (fp_) {
   std::fclose(fp_);
-    fp_ = nullptr;
-  }
   openMode_ = "r+b";
   opMode_ = opSeek;
   fp_ = std::fopen(path_.c_str(), openMode_.c_str());

src/image.cpp

@@ -786,7 +786,7 @@ ImageType ImageFactory::getType(BasicIo& io) {
   return ImageType::none;
 }
 
-BasicIo::UniquePtr ImageFactory::createIo(const std::string& path, bool useCurl) {
+BasicIo::UniquePtr ImageFactory::createIo(const std::string& path, [[maybe_unused]] bool useCurl) {
   Protocol fProt = fileProtocol(path);
 
 #ifdef EXV_USE_CURL
@@ -803,8 +803,6 @@ BasicIo::UniquePtr ImageFactory::createIo(const std::string& path, bool useCurl)
     return std::make_unique<XPathIo>(path);  // may throw
 
   return std::make_unique<FileIo>(path);
-
-  (void)(useCurl);
 }  // ImageFactory::createIo
 
 Image::UniquePtr ImageFactory::open(const std::string& path, bool useCurl) {

src/value.cpp

@@ -371,7 +371,7 @@ std::string CommentValue::comment(const char* encoding) const {
   if (charsetId() == unicode) {
     const char* from = !encoding || *encoding == '\0' ? detectCharset(c) : encoding;
     if (!convertStringCharset(c, from, "UTF-8"))
-      throw Error(ErrorCode::kerInvalidIconvEncoding, encoding, "UTF-8");
+      throw Error(ErrorCode::kerInvalidIconvEncoding, from, "UTF-8");
   }
 
   // # 1266 Remove trailing nulls

src/xmp.cpp

@@ -693,7 +693,6 @@ int XmpParser::decode(XmpData& xmpData, const std::string& xmpPacket) {
       printNode(schemaNs, propPath, propValue, opt);
       if (XMP_PropIsAlias(opt)) {
         throw Error(ErrorCode::kerAliasesNotSupported, schemaNs, propPath, propValue);
-        continue;
       }
       if (XMP_NodeIsSchema(opt)) {
         // Register unknown namespaces with Exiv2