fixed compiler warnings around "unsigned >= 0"

clang 2.9 detects comparisons which are always true, like "unsigned
value >= 0", and warns about them. In some cases the usage of a signed
type prevents detecting underflows (argidx = c-'1'), in another it
means that error handling was never done (fread() returns 0 on error,
not -1).

Fixed by switching (back?) to signed types and casting to unsigned
after sanity check and before comparison against other, real unsigned
types.

4 files changed, 8 insertions, 8 deletions

diff --git a/src/sysync/scriptcontext.cpp b/src/sysync/scriptcontext.cpp
index 7ea4fac..35dff88 100755
--- a/src/sysync/scriptcontext.cpp
+++ b/src/sysync/scriptcontext.cpp
@@ -2448,8 +2448,8 @@ void TScriptContext::Tokenize(TSyncAppBase *aAppBaseP, cAppCharP aScriptName, sI
           continue;
         }
         else if (isdigit(c)) {
-          size_t argidx = c-'1';
-          if (argidx>=0 && argidx<aMacroArgsP->size()) {
+          ssize_t argidx = c-'1';
+          if (argidx>=0 && (size_t)argidx<aMacroArgsP->size()) {
           	// found macro argument, replace in input string
             itext.replace(i-1, 2, (*aMacroArgsP)[argidx]);
             // no nested macro argument eval, just advance pointer behind replacement text
diff --git a/src/sysync/stringutils.cpp b/src/sysync/stringutils.cpp
index 6abacbd..1b42d76 100755
--- a/src/sysync/stringutils.cpp
+++ b/src/sysync/stringutils.cpp
@@ -796,7 +796,7 @@ void vStringObjPrintf(string &aStringObj, const char *aFormat, bool aAppend, va_
   #else
   const size_t bufsiz=2048;
   #endif
-  size_t actualsize;
+  ssize_t actualsize;
   char buf[bufsiz];
 
   buf[0]='\0';
@@ -810,7 +810,7 @@ void vStringObjPrintf(string &aStringObj, const char *aFormat, bool aAppend, va_
   #endif
   actualsize = vsnprintf(buf, bufsiz, aFormat, aArgs);
   #ifndef NO_VSNPRINTF
-  if (actualsize>=bufsiz) {
+  if (actualsize>=(ssize_t)bufsiz) {
     // default buffer was too small, create bigger dynamic buffer
     bufP = new char[actualsize+1];
     actualsize = vsnprintf(bufP, actualsize+1, aFormat, args);
diff --git a/src/sysync/syncappbase.cpp b/src/sysync/syncappbase.cpp
index c8d50c4..d99965b 100755
--- a/src/sysync/syncappbase.cpp
+++ b/src/sysync/syncappbase.cpp
@@ -1805,7 +1805,7 @@ static int _CALLING_ CFileReader(
   FILE *cfgfile = (FILE *)aContext;
   // read from file
   size_t len = fread(aBuffer, 1, aMaxSize, cfgfile);
-  if (len<0) {
+  if (len<=0) {
     if (!feof(cfgfile))
       return appFalse; // not EOF, other error: failed
     len=0; // nothing read, end of file
diff --git a/src/sysync_SDK/Sources/SDK_support.cpp b/src/sysync_SDK/Sources/SDK_support.cpp
index 49ef310..c54226d 100755
--- a/src/sysync_SDK/Sources/SDK_support.cpp
+++ b/src/sysync_SDK/Sources/SDK_support.cpp
@@ -571,15 +571,15 @@ CVersion VersionNr( string s )
 
 bool SameBegin( string s, string cmp )
 {
-  uInt32 w=      s.length()-cmp.length();
+  ssize_t w=      s.length()-cmp.length();
   return w>=0 && s.find   ( cmp, 0 )==0;
 } // SameBegin
 
 
 bool SameEnd  ( string s, string cmp )
 {
-  uInt32 w=      s.length()-cmp.length();
-  return w>=0 && s.find   ( cmp, w )==w;
+  ssize_t w=      s.length()-cmp.length();
+  return w>=0 && s.find   ( cmp, w )==(size_t)w;
 } // SameEnd