Simplify string building.

src/mtime_timedelta.c

@@ -1481,64 +1481,52 @@ getTotalSecondsTimeDelta(struct _timedelta* td, struct _datetime* base_dt)
 char *
 timedeltaToString(struct _timedelta* td, char* toStr)
 {
-  if ((td != NULL )&& (toStr != NULL) ){
-
+  if ((td != NULL )&& (toStr != NULL) && (td->sign == '+' || td->sign == '-')){
   memset(toStr,'\0',MAX_TIMEDELTA_STR_LEN);
 
+  int pos = 0;
   if (td->sign == '-')
-    sprintf(toStr,"%cP",td->sign);
-  else if (td->sign == '+')
-    strcpy (toStr,"P");
-  else
-    return NULL; /* ERROR: TD sign not set. Should never happen. */
-  
+    toStr[pos++] = '-';
+  toStr[pos++] = 'P';
+
+  if (td->second > 59)
+    {
+      /* generate string with seconds only */
+      toStr[pos++] = 'T';
+      sprintf(toStr+pos,"%d.%03dS",td->second, td->ms);
+      return toStr;
+    }
+
   if (td->year != 0)
-    sprintf(&(toStr[strlen(toStr)]),"%" PRIi64 "Y",td->year);
+    pos += sprintf(toStr+pos,"%" PRIi64 "Y",td->year);
 
   if (td->month != 0)
-    sprintf(&(toStr[strlen(toStr)]),"%02dM",td->month);
+    pos += sprintf(toStr+pos,"%02dM",td->month);
 
   if (td->day != 0)
-    sprintf(&(toStr[strlen(toStr)]),"%02dD",td->day);
+    pos += sprintf(toStr+pos,"%02dD",td->day);
 
-  sprintf(&(toStr[strlen(toStr)]),"T");
+  toStr[pos++] = 'T';
 
   if (td->hour != 0)
-    sprintf(&(toStr[strlen(toStr)]),"%02dH",td->hour);
+    pos += sprintf(toStr+pos,"%02dH",td->hour);
 
   if (td->minute != 0)
-    sprintf(&(toStr[strlen(toStr)]),"%02dM",td->minute);
+    pos += sprintf(toStr+pos,"%02dM",td->minute);
 
   if ((td->second != 0) || (td->ms != 0))
     {
-      if (td->second > 59)
-        {
-          /* reset and generate string with seconds only */
-          memset(toStr,'\0',MAX_TIMEDELTA_STR_LEN);
-
-          if (td->sign == '-')
-            sprintf(toStr,"%cPT",td->sign);
-          else if (td->sign == '+')
-            strcpy (toStr,"PT");
-          else
-            return NULL; /*ERROR: TD sign not set. Should never happen. */
-
-          sprintf(&(toStr[strlen(toStr)]),"%d.%03dS",td->second, td->ms);
-        }
-      else
-        {
-          sprintf(&(toStr[strlen(toStr)]),"%02d.%03dS",td->second,td->ms);
-        }
+      pos += sprintf(toStr+pos,"%02d.%03dS",td->second,td->ms);
     }
 
 
   //Discard T if all time values are 0.
-  if(toStr[strlen(toStr)-1] == 'T')
-    toStr[strlen(toStr)-1] = '\0';
+  if(toStr[pos-1] == 'T')
+    toStr[--pos] = '\0';
 
   //Return PT00.000S if all delta values are 0.
-  if(toStr[strlen(toStr)-1] == 'P')
-    strcat(toStr,"T00.000S");
+  if(toStr[pos-1] == 'P')
+    strcpy(toStr+pos,"T00.000S");
 
   return toStr;
 }