r13971: Fix Coverity bugs #209 - #213 - it detected mistakes

in the pointer aliasing once realloc could change
a pointer. This was in the bugzilla.samba.org database
as #687 but we never figured out what it was !
Jeremy.
(This used to be commit 8d183441403524fe39e79af843d6cfe65898f7d3)

diff --git a/source3/lib/substitute.c b/source3/lib/substitute.c
index 30e1d97ca9b29e4245fbe3b9e0ef74b42f0b6710..23b204d02460101326bf7d213403a753e66c5cf1 100644 (file)
--- a/source3/lib/substitute.c
+++ b/source3/lib/substitute.c
@@ -532,7 +532,9 @@ char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *st
 {
        char *a, *t;
                a = alloc_sub_basic(smb_name, str);
-       if (!a) return NULL;
+       if (!a) {
+               return NULL;
+       }
        t = talloc_strdup(mem_ctx, a);
        SAFE_FREE(a);
        return t;
@@ -540,14 +542,14 @@ char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name, const char *st
 
 char *alloc_sub_basic(const char *smb_name, const char *str)
 {
-       char *b, *p, *s, *t, *r, *a_string;
+       char *b, *p, *s, *r, *a_string;
        fstring pidstr;
        struct passwd *pass;
        const char *local_machine_name = get_local_machine_name();
 
-       /* workaround to prevent a crash while lookinf at bug #687 */
+       /* workaround to prevent a crash while looking at bug #687 */
        
-       if ( !str ) {
+       if (!str) {
                DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
                return NULL;
        }
@@ -561,68 +563,75 @@ char *alloc_sub_basic(const char *smb_name, const char *str)
        for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 
                r = NULL;
-               b = t = a_string;
+               b = a_string;
                
                switch (*(p+1)) {
                case 'U' : 
                        r = strdup_lower(smb_name);
-                       if (r == NULL) goto error;
-                       t = realloc_string_sub(t, "%U", r);
+                       if (r == NULL) {
+                               goto error;
+                       }
+                       a_string = realloc_string_sub(a_string, "%U", r);
                        break;
                case 'G' :
                        r = SMB_STRDUP(smb_name);
-                       if (r == NULL) goto error;
+                       if (r == NULL) {
+                               goto error;
+                       }
                        if ((pass = Get_Pwnam(r))!=NULL) {
-                               t = realloc_string_sub(t, "%G", gidtoname(pass->pw_gid));
+                               a_string = realloc_string_sub(a_string, "%G", gidtoname(pass->pw_gid));
                        } 
                        break;
                case 'D' :
                        r = strdup_upper(current_user_info.domain);
-                       if (r == NULL) goto error;
-                       t = realloc_string_sub(t, "%D", r);
+                       if (r == NULL) {
+                               goto error;
+                       }
+                       a_string = realloc_string_sub(a_string, "%D", r);
                        break;
                case 'I' :
-                       t = realloc_string_sub(t, "%I", client_addr());
+                       a_string = realloc_string_sub(a_string, "%I", client_addr());
                        break;
                case 'L' : 
-                       if (local_machine_name && *local_machine_name)
-                               t = realloc_string_sub(t, "%L", local_machine_name); 
-                       else
-                               t = realloc_string_sub(t, "%L", global_myname()); 
+                       if (local_machine_name && *local_machine_name) {
+                               a_string = realloc_string_sub(a_string, "%L", local_machine_name); 
+                       } else {
+                               a_string = realloc_string_sub(a_string, "%L", global_myname()); 
+                       }
                        break;
                case 'N':
-                       t = realloc_string_sub(t, "%N", automount_server(smb_name));
+                       a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
                        break;
                case 'M' :
-                       t = realloc_string_sub(t, "%M", client_name());
+                       a_string = realloc_string_sub(a_string, "%M", client_name());
                        break;
                case 'R' :
-                       t = realloc_string_sub(t, "%R", remote_proto);
+                       a_string = realloc_string_sub(a_string, "%R", remote_proto);
                        break;
                case 'T' :
-                       t = realloc_string_sub(t, "%T", timestring(False));
+                       a_string = realloc_string_sub(a_string, "%T", timestring(False));
                        break;
                case 'a' :
-                       t = realloc_string_sub(t, "%a", remote_arch);
+                       a_string = realloc_string_sub(a_string, "%a", remote_arch);
                        break;
                case 'd' :
                        slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
-                       t = realloc_string_sub(t, "%d", pidstr);
+                       a_string = realloc_string_sub(a_string, "%d", pidstr);
                        break;
                case 'h' :
-                       t = realloc_string_sub(t, "%h", myhostname());
+                       a_string = realloc_string_sub(a_string, "%h", myhostname());
                        break;
                case 'm' :
-                       t = realloc_string_sub(t, "%m", remote_machine);
+                       a_string = realloc_string_sub(a_string, "%m", remote_machine);
                        break;
                case 'v' :
-                       t = realloc_string_sub(t, "%v", SAMBA_VERSION_STRING);
+                       a_string = realloc_string_sub(a_string, "%v", SAMBA_VERSION_STRING);
                        break;
                case 'w' :
-                       t = realloc_string_sub(t, "%w", lp_winbind_separator());
+                       a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
                        break;
                case '$' :
-                       t = realloc_expand_env_var(t, p); /* Expand environment variables */
+                       a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
                        break;
                        
                default: 
@@ -631,11 +640,13 @@ char *alloc_sub_basic(const char *smb_name, const char *str)
 
                p++;
                SAFE_FREE(r);
-               if (t == NULL) goto error;
-               a_string = t;
+               if (a_string == NULL) {
+                       return NULL;
+               }
        }
 
        return a_string;
+
 error:
        SAFE_FREE(a_string);
        return NULL;
@@ -655,7 +666,9 @@ char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 {
        char *a, *t;
                a = alloc_sub_specified(input_string, username, domain, uid, gid);
-       if (!a) return NULL;
+       if (!a) {
+               return NULL;
+       }
        t = talloc_strdup(mem_ctx, a);
        SAFE_FREE(a);
        return t;
@@ -668,7 +681,7 @@ char *alloc_sub_specified(const char *input_string,
                        gid_t gid)
 {
        char *a_string, *ret_string;
-       char *b, *p, *s, *t;
+       char *b, *p, *s;
 
        a_string = SMB_STRDUP(input_string);
        if (a_string == NULL) {
@@ -678,45 +691,43 @@ char *alloc_sub_specified(const char *input_string,
        
        for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
                
-               b = t = a_string;
+               b = a_string;
                
                switch (*(p+1)) {
                case 'U' : 
-                       t = realloc_string_sub(t, "%U", username);
+                       a_string = realloc_string_sub(a_string, "%U", username);
                        break;
                case 'u' : 
-                       t = realloc_string_sub(t, "%u", username);
+                       a_string = realloc_string_sub(a_string, "%u", username);
                        break;
                case 'G' :
                        if (gid != -1) {
-                               t = realloc_string_sub(t, "%G", gidtoname(gid));
+                               a_string = realloc_string_sub(a_string, "%G", gidtoname(gid));
                        } else {
-                               t = realloc_string_sub(t, "%G", "NO_GROUP");
+                               a_string = realloc_string_sub(a_string, "%G", "NO_GROUP");
                        }
                        break;
                case 'g' :
                        if (gid != -1) {
-                               t = realloc_string_sub(t, "%g", gidtoname(gid));
+                               a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
                        } else {
-                               t = realloc_string_sub(t, "%g", "NO_GROUP");
+                               a_string = realloc_string_sub(a_string, "%g", "NO_GROUP");
                        }
                        break;
                case 'D' :
-                       t = realloc_string_sub(t, "%D", domain);
+                       a_string = realloc_string_sub(a_string, "%D", domain);
                        break;
                case 'N' : 
-                       t = realloc_string_sub(t, "%N", automount_server(username)); 
+                       a_string = realloc_string_sub(a_string, "%N", automount_server(username)); 
                        break;
                default: 
                        break;
                }
 
                p++;
-               if (t == NULL) {
-                       SAFE_FREE(a_string);
+               if (a_string == NULL) {
                        return NULL;
                }
-               a_string = t;
        }
 
        ret_string = alloc_sub_basic(username, a_string);
@@ -734,7 +745,9 @@ char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 {
        char *a, *t;
                a = alloc_sub_advanced(snum, user, connectpath, gid, smb_name, str);
-       if (!a) return NULL;
+       if (!a) {
+               return NULL;
+       }
        t = talloc_strdup(mem_ctx, a);
        SAFE_FREE(a);
        return t;
@@ -745,7 +758,7 @@ char *alloc_sub_advanced(int snum, const char *user,
                                  const char *smb_name, const char *str)
 {
        char *a_string, *ret_string;
-       char *b, *p, *s, *t, *h;
+       char *b, *p, *s, *h;
 
        a_string = SMB_STRDUP(str);
        if (a_string == NULL) {
@@ -755,27 +768,27 @@ char *alloc_sub_advanced(int snum, const char *user,
        
        for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
                
-               b = t = a_string;
+               b = a_string;
                
                switch (*(p+1)) {
                case 'N' :
-                       t = realloc_string_sub(t, "%N", automount_server(user));
+                       a_string = realloc_string_sub(a_string, "%N", automount_server(user));
                        break;
                case 'H':
                        if ((h = get_user_home_dir(user)))
-                               t = realloc_string_sub(t, "%H", h);
+                               a_string = realloc_string_sub(a_string, "%H", h);
                        break;
                case 'P': 
-                       t = realloc_string_sub(t, "%P", connectpath); 
+                       a_string = realloc_string_sub(a_string, "%P", connectpath); 
                        break;
                case 'S': 
-                       t = realloc_string_sub(t, "%S", lp_servicename(snum)); 
+                       a_string = realloc_string_sub(a_string, "%S", lp_servicename(snum)); 
                        break;
                case 'g': 
-                       t = realloc_string_sub(t, "%g", gidtoname(gid)); 
+                       a_string = realloc_string_sub(a_string, "%g", gidtoname(gid)); 
                        break;
                case 'u': 
-                       t = realloc_string_sub(t, "%u", user); 
+                       a_string = realloc_string_sub(a_string, "%u", user); 
                        break;
                        
                        /* Patch from jkf@soton.ac.uk Left the %N (NIS
@@ -786,7 +799,7 @@ char *alloc_sub_advanced(int snum, const char *user,
                         * "path =" string in [homes] and so needs the
                         * service name, not the username.  */
                case 'p': 
-                       t = realloc_string_sub(t, "%p", automount_path(lp_servicename(snum))); 
+                       a_string = realloc_string_sub(a_string, "%p", automount_path(lp_servicename(snum))); 
                        break;
                        
                default: 
@@ -794,11 +807,9 @@ char *alloc_sub_advanced(int snum, const char *user,
                }
 
                p++;
-               if (t == NULL) {
-                       SAFE_FREE(a_string);
+               if (a_string == NULL) {
                        return NULL;
                }
-               a_string = t;
        }
 
        ret_string = alloc_sub_basic(smb_name, a_string);