Replace malloc/memcpy with strdup in EnvironPutenv.

src/pal/src/misc/environ.cpp

@@ -782,36 +782,37 @@ Return Values
 --*/
 BOOL EnvironPutenv(const char* entry, BOOL deleteIfEmpty)
 {
-    bool fOwningCS = false;
     BOOL result = FALSE;
 
+    bool fOwningCS = false;
+
     CPalThread * pthrCurrent = InternalGetCurrentThread();
 
     const char *equalsSignPosition = strchr(entry, '=');
     if (equalsSignPosition == entry || equalsSignPosition == nullptr)
     {
         // "=foo" and "foo" have no meaning
-        goto done;
+        return FALSE;
     }
 
+    char* copy = strdup(entry);
+    if (copy == nullptr)
+    {
+        return FALSE;
+    }
+
+    int nameLength = equalsSignPosition - entry;
+
     if (equalsSignPosition[1] == '\0' && deleteIfEmpty)
     {
         // "foo=" removes foo from the environment in _putenv() on Windows.
         // The same string can result from a call to SetEnvironmentVariable()
         // with the empty string as the value, but in that case we want to
         // set the variable's value to "". deleteIfEmpty will be FALSE in
         // that case.
-        int length = strlen(entry);
-        char* copy = (char *) InternalMalloc(length);
-        if (copy == nullptr)
-        {
-            goto done;
-        }
-
-        memcpy(copy, entry, length - 1);
 
         // Change '=' to '\0'
-        copy[length - 1] = '\0';
+        copy[nameLength] = '\0';
 
         EnvironUnsetenv(copy);
         InternalFree(copy);
@@ -822,15 +823,6 @@ BOOL EnvironPutenv(const char* entry, BOOL deleteIfEmpty)
     {
         // See if we are replacing an item or adding one.
 
-        // Make our copy up front, since we'll use it either way.
-        char* copy = strdup(entry);
-        if (copy == nullptr)
-        {
-            goto done;
-        }
-
-        int nameLength = equalsSignPosition - entry;
-
         InternalEnterCriticalSection(pthrCurrent, &gcsEnvironment);
         fOwningCS = true;
 
@@ -1010,14 +1002,20 @@ EnvironInitialize(void)
     // space for all of the 'n' current environment variables, but we don't
     // know how many more there will be, we will initially make room for
     // '2n' variables. If even more are added, we will resize again.
-    ResizeEnvironment(variableCount * 2);
+    // If there are no variables, we will still make room for 1 entry to 
+    // store a nullptr there.
+    int initialSize = (variableCount == 0) ? 1 : variableCount * 2;
+    ResizeEnvironment(initialSize);
 
     for (int i = 0; i < variableCount; ++i)
     {
         palEnvironment[i] = strdup(sourceEnviron[i]);
         palEnvironmentCount++;
     }
 
+    // Set the entry after the last variable to null to indicate the end.
+    palEnvironment[variableCount] = nullptr;
+
     InternalLeaveCriticalSection(pthrCurrent, &gcsEnvironment);
 
     return TRUE;