From d985a6924841c9e67e2dbd4a8b644c9ea5a2f18a Mon Sep 17 00:00:00 2001
From: Lew Rossman <LRossman@cinci.rr.com>
Date: Sat, 20 Apr 2019 11:54:33 -0400
Subject: [PATCH] Refactored xstrcpy function

---
 src/project.c | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/src/project.c b/src/project.c
index faa3eaf..f98be65 100644
--- a/src/project.c
+++ b/src/project.c
@@ -7,7 +7,7 @@
  Authors:      see AUTHORS
  Copyright:    see AUTHORS
  License:      see LICENSE
- Last Updated: 04/18/2019
+ Last Updated: 04/20/2019
  ******************************************************************************
 */
 
@@ -805,7 +805,7 @@ void adjustpatterns(Network *network, int index)
     Psource source;
 
     // Adjust patterns used by junctions
-    for (j = 1; j <= network->Njuncs; j++)
+    for (j = 1; j <= network->Nnodes; j++)
     {
         // Adjust demand patterns
         for (demand = network->Node[j].D; demand != NULL; demand = demand->next)
@@ -1039,33 +1039,37 @@ char *xstrcpy(char **s1, const char *s2, const size_t n)
 //           n = maximum size of strings
 //  Output:  none
 //  Purpose: like strcpy except for dynamic strings.
+//  Note:    The calling program is responsible for ensuring that
+//           s1 points to a valid memory location or is NULL. E.g.,
+//           the following code will likely cause a segment fault:
+//             char *s;
+//             s = xstrcpy(s, "Some text");
+//           while this would work correctly:
+//             char *s = NULL;
+//             s = xstrcpy(s, "Some text");
 //----------------------------------------------------------------
 {
-    size_t n1 = 0, n2;
+    size_t n1 = 0, n2 = 0;
+
+    // Find size of source string
+    if (s2) n2 = strlen(s2);
+    if (n2 > n) n2 = n;
 
     // Source string is empty -- free destination string
-    if (s2 == NULL || strlen(s2) == 0)
+    if (n2 == 0)
     {
         free(*s1);
+        *s1 = NULL;
         return NULL;
     }
 
-    // Source string not empty -- overwrite destination string
-    else
-    {
-        // See if size of destination string needs to grow
-        if (*s1) n1 = strlen(*s1);
-        if ((n2 = strlen(s2)) > n) n2 = n;
-        if (n2 > n1)
-        {
-            free(*s1);
-            *s1 = (char *)malloc((n2 + 1) * sizeof(char));
-        }
+    // See if size of destination string needs to grow
+    if (*s1) n1 = strlen(*s1);
+    if (n2 > n1) *s1 = realloc(*s1, (n2 + 1) * sizeof(char));
 
-        // Copy the new comment string into the existing one
-        if (*s1) strcpy(*s1, s2);
-        return *s1;
-    }
+    // Copy the source string into the destination string
+    strcpy(*s1, s2);
+    return *s1;
 }
 
 int strcomp(const char *s1, const char *s2)