Fix fcaseopen.c buffer overflow

Nexus/fcaseopen.c

@@ -30,75 +30,68 @@ THE SOFTWARE.
 #include <errno.h>
 #include <unistd.h>
 
-// r must have strlen(path) + 2 bytes
+// r must have strlen(path) + 3 bytes
 static int casepath(char const *path, char *r)
 {
     size_t l = strlen(path);
-    char *p = (char*)alloca(l + 1);
+    char *p  = (char *)alloca(l + 1);
     strcpy(p, path);
     size_t rl = 0;
-    
+
     DIR *d;
-    if (p[0] == '/')
-    {
+    if (p[0] == '/') {
         d = opendir("/");
         p = p + 1;
     }
-    else
-    {
-        d = opendir(".");
+    else {
+        d    = opendir(".");
         r[0] = '.';
         r[1] = 0;
-        rl = 1;
+        rl   = 1;
     }
-    
+
     int last = 0;
-    char *c = strsep(&p, "/");
-    while (c)
-    {
-        if (!d)
-        {
+    char *c  = strsep(&p, "/");
+    while (c) {
+        if (!d) {
             return 0;
         }
-
-        if (last)
-        {
+
+        if (last) {
             closedir(d);
             return 0;
         }
-        
+
         r[rl] = '/';
         rl += 1;
         r[rl] = 0;
-        
+
         struct dirent *e = readdir(d);
-        while (e)
-        {
-            if (strcasecmp(c, e->d_name) == 0)
-            {
+        while (e) {
+            if (strcasecmp(c, e->d_name) == 0) {
                 strcpy(r + rl, e->d_name);
                 rl += strlen(e->d_name);
 
                 closedir(d);
                 d = opendir(r);
-                
+
                 break;
             }
-            
+
             e = readdir(d);
         }
-
-        if (!e)
-        {
+
+        if (!e) {
             strcpy(r + rl, c);
             rl += strlen(c);
             last = 1;
         }
-        
+
         c = strsep(&p, "/");
     }
-
-    if (d) closedir(d);
+
+    if (d)
+        closedir(d);
     return 1;
 }
 #endif
@@ -107,11 +100,9 @@ FILE *fcaseopen(char const *path, char const *mode)
 {
     FILE *f = fopen(path, mode);
 #if !defined(_WIN32)
-    if (!f)
-    {	    
-        char *r = (char*)alloca(strlen(path) + 2);
-        if (casepath(path, r))
-        {
+    if (!f) {
+        char *r = (char *)alloca(strlen(path) + 3);
+        if (casepath(path, r)) {
             f = fopen(r, mode);
         }
     }
@@ -122,13 +113,11 @@ FILE *fcaseopen(char const *path, char const *mode)
 void casechdir(char const *path)
 {
 #if !defined(_WIN32)
-    char *r = (char*)alloca(strlen(path) + 2);
-    if (casepath(path, r))
-    {
+    char *r = (char *)alloca(strlen(path) + 3);
+    if (casepath(path, r)) {
         chdir(r);
     }
-    else
-    {
+    else {
         errno = ENOENT;
     }
 #else