Fix implicit sign conversion in num_procs code

Author: joto

src/options.cpp

@@ -318,6 +318,24 @@ static osmium::Box parse_bbox(char const *bbox)
     return osmium::Box{minx, miny, maxx, maxy};
 }
 
+static unsigned int number_of_threads(char const *arg)
+{
+    int num = atoi(arg);
+    if (num < 1) {
+        log_warn("--number-processes must be at least 1. Using 1.");
+        num = 1;
+    } else if (num > 32) {
+        // The threads will open up database connections which will
+        // run out at some point. It depends on the number of tables
+        // how many connections there are. The number 32 is way beyond
+        // anything that will make sense here.
+        log_warn("--number-processes too large. Set to 32.");
+        num = 32;
+    }
+
+    return static_cast<unsigned int>(num);
+}
+
 options_t::options_t(int argc, char *argv[]) : options_t()
 {
     // If there are no command line arguments at all, show help.
@@ -503,18 +521,7 @@ options_t::options_t(int argc, char *argv[]) : options_t()
             log_warn("Deprecated option --cache-strategy ignored");
             break;
         case 205:
-            num_procs = atoi(optarg);
-            if (num_procs < 1) {
-                log_warn("--number-processes must be at least 1. Using 1.");
-                num_procs = 1;
-            } else if (num_procs > 32) {
-                // The threads will open up database connections which will
-                // run out at some point. It depends on the number of tables
-                // how many connections there are. The number 32 is way beyond
-                // anything that will make sense here.
-                log_warn("--number-processes too large. Set to 32.");
-                num_procs = 32;
-            }
+            num_procs = number_of_threads(optarg);
             break;
         case 206:
             droptemp = true;

src/osmdata.cpp

@@ -347,8 +347,7 @@ class multithreaded_processor
 
 void osmdata_t::process_dependents() const
 {
-    multithreaded_processor proc{m_conninfo, m_mid, m_output,
-                                 (std::size_t)m_num_procs};
+    multithreaded_processor proc{m_conninfo, m_mid, m_output, m_num_procs};
 
     // stage 1b processing: process parents of changed objects
     if (m_dependency_manager->has_pending()) {

src/osmdata.hpp

@@ -98,7 +98,7 @@ class osmdata_t : public osmium::handler::Handler
     // imported).
     osmium::Box m_bbox;
 
-    int m_num_procs;
+    unsigned int m_num_procs;
     bool m_append;
     bool m_droptemp;
     bool m_parallel_indexing;