new loplugin:stringloop, and applied in various

look for OUString being appended to in a loop, better to use
OUStringBuffer to accumulate the results.

Change-Id: Ia36e06e2781a7c546ce9cbad62727aa4c5f10c4b
Reviewed-on: https://gerrit.libreoffice.org/58092
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

4 files changed, 29 insertions, 27 deletions

diff --git a/svl/source/items/slstitm.cxx b/svl/source/items/slstitm.cxx
index 5399706c2e85..64d960226d86 100644
--- a/svl/source/items/slstitm.cxx
+++ b/svl/source/items/slstitm.cxx
@@ -25,6 +25,7 @@
 #include <osl/diagnose.h>
 #include <tools/stream.hxx>
 #include <stringio.hxx>
+#include <rtl/ustrbuf.hxx>
 
 SfxPoolItem* SfxStringListItem::CreateDefault() { return new SfxStringListItem; }
 
@@ -165,22 +166,22 @@ void SfxStringListItem::SetString( const OUString& rStr )
 
 OUString SfxStringListItem::GetString()
 {
-    OUString aStr;
+    OUStringBuffer aStr;
     if ( mpList )
     {
         std::vector<OUString>::const_iterator iter = mpList->begin();
         for (;;)
         {
-            aStr += *iter;
+            aStr.append(*iter);
             ++iter;
 
             if (iter == mpList->end())
                 break;
 
-            aStr += "\r";
+            aStr.append("\r");
         }
     }
-    return convertLineEnd(aStr, GetSystemLineEnd());
+    return convertLineEnd(aStr.makeStringAndClear(), GetSystemLineEnd());
 }
 
 
diff --git a/svl/source/items/style.cxx b/svl/source/items/style.cxx
index 5856393f57e9..0ab10a4c7801 100644
--- a/svl/source/items/style.cxx
+++ b/svl/source/items/style.cxx
@@ -36,6 +36,7 @@
 #include <algorithm>
 #include <comphelper/servicehelper.hxx>
 #include <o3tl/make_unique.hxx>
+#include <rtl/ustrbuf.hxx>
 
 #include <string.h>
 
@@ -328,7 +329,7 @@ bool SfxStyleSheetBase::IsUsed() const
 OUString SfxStyleSheetBase::GetDescription( MapUnit eMetric )
 {
     SfxItemIter aIter( GetItemSet() );
-    OUString aDesc;
+    OUStringBuffer aDesc;
     const SfxPoolItem* pItem = aIter.FirstItem();
 
     IntlWrapper aIntlWrapper(SvtSysLocale().GetUILanguageTag());
@@ -341,13 +342,13 @@ OUString SfxStyleSheetBase::GetDescription( MapUnit eMetric )
                 *pItem, eMetric, aItemPresentation, aIntlWrapper ) )
         {
             if ( !aDesc.isEmpty() && !aItemPresentation.isEmpty() )
-                aDesc += " + ";
+                aDesc.append(" + ");
             if ( !aItemPresentation.isEmpty() )
-                aDesc += aItemPresentation;
+                aDesc.append(aItemPresentation);
         }
         pItem = aIter.NextItem();
     }
-    return aDesc;
+    return aDesc.makeStringAndClear();
 }
 
 SfxStyleFamily SfxStyleSheetIterator::GetSearchFamily() const
diff --git a/svl/source/numbers/zformat.cxx b/svl/source/numbers/zformat.cxx
index 213e83a60a8c..f9e0b944b615 100644
--- a/svl/source/numbers/zformat.cxx
+++ b/svl/source/numbers/zformat.cxx
@@ -1930,7 +1930,7 @@ bool SvNumberformat::GetNewCurrencySymbol( OUString& rSymbol,
 // static
 OUString SvNumberformat::StripNewCurrencyDelimiters( const OUString& rStr )
 {
-    OUString aTmp;
+    OUStringBuffer aTmp;
     sal_Int32 nStartPos, nPos, nLen;
     nLen = rStr.getLength();
     nStartPos = 0;
@@ -1939,12 +1939,12 @@ OUString SvNumberformat::StripNewCurrencyDelimiters( const OUString& rStr )
         sal_Int32 nEnd;
         if ( (nEnd = GetQuoteEnd( rStr, nPos )) >= 0 )
         {
-            aTmp += rStr.copy( nStartPos, ++nEnd - nStartPos );
+            aTmp.append(rStr.copy( nStartPos, ++nEnd - nStartPos ));
             nStartPos = nEnd;
         }
         else
         {
-            aTmp += rStr.copy( nStartPos, nPos - nStartPos );
+            aTmp.append(rStr.copy( nStartPos, nPos - nStartPos ));
             nStartPos = nPos + 2;
             sal_Int32 nDash;
             nEnd = nStartPos - 1;
@@ -1975,15 +1975,15 @@ OUString SvNumberformat::StripNewCurrencyDelimiters( const OUString& rStr )
             {
                 nPos = nDash;
             }
-            aTmp += rStr.copy( nStartPos, nPos - nStartPos );
+            aTmp.append(rStr.copy( nStartPos, nPos - nStartPos ));
             nStartPos = nClose + 1;
         }
     }
     if ( nLen > nStartPos )
     {
-        aTmp += rStr.copy( nStartPos, nLen - nStartPos );
+        aTmp.append(rStr.copy( nStartPos, nLen - nStartPos ));
     }
-    return aTmp;
+    return aTmp.makeStringAndClear();
 }
 
 void SvNumberformat::ImpGetOutputStandard(double& fNumber, OUStringBuffer& rOutString) const
diff --git a/svl/source/passwordcontainer/passwordcontainer.cxx b/svl/source/passwordcontainer/passwordcontainer.cxx
index 6becfd9be78d..3a4aecef9874 100644
--- a/svl/source/passwordcontainer/passwordcontainer.cxx
+++ b/svl/source/passwordcontainer/passwordcontainer.cxx
@@ -36,6 +36,7 @@
 #include <rtl/cipher.h>
 #include <rtl/digest.h>
 #include <rtl/byteseq.hxx>
+#include <rtl/ustrbuf.hxx>
 
 using namespace osl;
 using namespace utl;
@@ -48,12 +49,12 @@ using namespace com::sun::star::ucb;
 
 static OUString createIndex(const std::vector< OUString >& lines)
 {
-    OUString aResult;
+    OUStringBuffer aResult;
 
     for( size_t i = 0; i < lines.size(); i++ )
     {
         if( i )
-            aResult += "__";
+            aResult.append("__");
         OString line = OUStringToOString( lines[i], RTL_TEXTENCODING_UTF8 );
         const sal_Char* pLine = line.getStr();
 
@@ -61,19 +62,18 @@ static OUString createIndex(const std::vector< OUString >& lines)
         {
             if (rtl::isAsciiAlphanumeric(static_cast<unsigned char>(*pLine)))
             {
-                aResult += OUStringLiteral1(*pLine);
+                aResult.append(*pLine);
             }
             else
             {
-                aResult += "_"
-                        + OUString::number(  *pLine, 16 );
+                aResult.append("_").append( OUString::number(  *pLine, 16 ) );
             }
 
             pLine++;
         }
     }
 
-    return aResult;
+    return aResult.makeStringAndClear();
 }
 
 
@@ -86,7 +86,7 @@ static std::vector< OUString > getInfoFromInd( const OUString& aInd )
     const sal_Char* pLine = line.getStr();
     do
     {
-        OUString newItem;
+        OUStringBuffer newItem;
         if( !aStart )
             pLine += 2;
         else
@@ -95,7 +95,7 @@ static std::vector< OUString > getInfoFromInd( const OUString& aInd )
         while( *pLine && !( pLine[0] == '_' && pLine[1] == '_' ))
             if( *pLine != '_' )
             {
-                newItem += OUStringLiteral1( *pLine );
+                newItem.append( *pLine );
                 pLine++;
             }
             else
@@ -115,11 +115,11 @@ static std::vector< OUString > getInfoFromInd( const OUString& aInd )
                     aNum += OUStringLiteral1( pLine[i] );
                 }
 
-                newItem += OUStringLiteral1( aNum.toUInt32( 16 ) );
+                newItem.append( OUStringLiteral1( aNum.toUInt32( 16 ) ) );
                 pLine += 3;
             }
 
-        aResult.push_back( newItem );
+        aResult.push_back( newItem.makeStringAndClear() );
     } while( pLine[0] == '_' && pLine[1] == '_' );
 
     if( *pLine )
@@ -766,11 +766,11 @@ UrlRecord PasswordContainer::find(
 
 OUString PasswordContainer::GetDefaultMasterPassword()
 {
-    OUString aResult;
+    OUStringBuffer aResult;
     for ( sal_Int32 nInd = 0; nInd < RTL_DIGEST_LENGTH_MD5; nInd++ )
-        aResult += "aa";
+        aResult.append("aa");
 
-    return aResult;
+    return aResult.makeStringAndClear();
 }
 
 OUString PasswordContainer::RequestPasswordFromUser( PasswordRequestMode aRMode, const uno::Reference< task::XInteractionHandler >& xHandler )