Backed out f1a91825730a and 7094bd12c1ff. While ngx_get_full_name() might have a bit more descriptive arguments, the ngx_conf_full_name() is generally easier to use when parsing configuration and limits exposure of cycle->prefix / cycle->conf_prefix details.

diff --git a/src/core/nginx.c b/src/core/nginx.c
index 9cabac1..4cc8082 100644
--- a/src/core/nginx.c
+++ b/src/core/nginx.c

@@ -897,9 +897,7 @@
         ngx_str_set(&cycle->conf_file, NGX_CONF_PATH);
     }
 
-    if (ngx_get_full_name(cycle->pool, &cycle->prefix, &cycle->conf_file)
-        != NGX_OK)
-    {
+    if (ngx_conf_full_name(cycle, &cycle->conf_file, 0) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -1015,7 +1013,7 @@
         ngx_str_set(&ccf->pid, NGX_PID_PATH);
     }
 
-    if (ngx_get_full_name(cycle->pool, &cycle->prefix, &ccf->pid) != NGX_OK) {
+    if (ngx_conf_full_name(cycle, &ccf->pid, 0) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 
@@ -1063,9 +1061,7 @@
         ngx_str_set(&ccf->lock_file, NGX_LOCK_PATH);
     }
 
-    if (ngx_get_full_name(cycle->pool, &cycle->prefix, &ccf->lock_file)
-        != NGX_OK)
-    {
+    if (ngx_conf_full_name(cycle, &ccf->lock_file, 0) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 

diff --git a/src/core/ngx_conf_file.c b/src/core/ngx_conf_file.c
index afa27d7..6cfb5d5 100644
--- a/src/core/ngx_conf_file.c
+++ b/src/core/ngx_conf_file.c

@@ -747,7 +747,7 @@
 
     ngx_log_debug1(NGX_LOG_DEBUG_CORE, cf->log, 0, "include %s", file.data);
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, &file) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, &file, 1) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 
@@ -797,6 +797,16 @@
 }
 
 
+ngx_int_t
+ngx_conf_full_name(ngx_cycle_t *cycle, ngx_str_t *name, ngx_uint_t conf_prefix)
+{
+    return ngx_get_full_name(cycle->pool,
+                             conf_prefix ? &cycle->conf_prefix:
+                                           &cycle->prefix,
+                             name);
+}
+
+
 ngx_open_file_t *
 ngx_conf_open_file(ngx_cycle_t *cycle, ngx_str_t *name)
 {
@@ -812,7 +822,7 @@
     if (name->len) {
         full = *name;
 
-        if (ngx_get_full_name(cycle->pool, &cycle->prefix, &full) != NGX_OK) {
+        if (ngx_conf_full_name(cycle, &full, 0) != NGX_OK) {
             return NULL;
         }
 

diff --git a/src/core/ngx_conf_file.h b/src/core/ngx_conf_file.h
index f0a12d4..d73a6c8 100644
--- a/src/core/ngx_conf_file.h
+++ b/src/core/ngx_conf_file.h

@@ -311,6 +311,8 @@
 char *ngx_conf_include(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
 
 
+ngx_int_t ngx_conf_full_name(ngx_cycle_t *cycle, ngx_str_t *name,
+    ngx_uint_t conf_prefix);
 ngx_open_file_t *ngx_conf_open_file(ngx_cycle_t *cycle, ngx_str_t *name);
 void ngx_cdecl ngx_conf_log_error(ngx_uint_t level, ngx_conf_t *cf,
     ngx_err_t err, const char *fmt, ...);

diff --git a/src/core/ngx_file.c b/src/core/ngx_file.c
index 049b876..28e8871 100644
--- a/src/core/ngx_file.c
+++ b/src/core/ngx_file.c

@@ -355,9 +355,7 @@
         path->name.len--;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &path->name)
-        != NGX_OK)
-    {
+    if (ngx_conf_full_name(cf->cycle, &path->name, 0) != NGX_OK) {
         return NULL;
     }
 
@@ -411,9 +409,7 @@
 
     (*path)->name = init->name;
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &(*path)->name)
-        != NGX_OK)
-    {
+    if (ngx_conf_full_name(cf->cycle, &(*path)->name, 0) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index 1459eea..50746e7 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c

@@ -240,7 +240,7 @@
     X509    *x509;
     u_long   n;
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, cert) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -319,7 +319,7 @@
 
     BIO_free(bio);
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, key) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, key, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -350,7 +350,7 @@
         return NGX_OK;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, cert) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -394,7 +394,7 @@
         return NGX_OK;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, cert) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, cert, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -421,7 +421,7 @@
         return NGX_OK;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, crl) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, crl, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 
@@ -587,7 +587,7 @@
         return NGX_OK;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, file) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, file, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 

diff --git a/src/event/ngx_event_openssl_stapling.c b/src/event/ngx_event_openssl_stapling.c
index f02eab6..7707614 100644
--- a/src/event/ngx_event_openssl_stapling.c
+++ b/src/event/ngx_event_openssl_stapling.c

@@ -197,7 +197,7 @@
 
     staple = SSL_CTX_get_ex_data(ssl->ctx, ngx_ssl_stapling_index);
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, file) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, file, 1) != NGX_OK) {
         return NGX_ERROR;
     }
 

diff --git a/src/http/modules/ngx_http_geo_module.c b/src/http/modules/ngx_http_geo_module.c
index 711871b..34c3b19 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c

@@ -1327,7 +1327,7 @@
 
     ngx_sprintf(file.data, "%V.bin%Z", name);
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->conf_prefix, &file) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, &file, 1) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 

diff --git a/src/http/modules/ngx_http_log_module.c b/src/http/modules/ngx_http_log_module.c
index 505ae3b..aa6a3fc 100644
--- a/src/http/modules/ngx_http_log_module.c
+++ b/src/http/modules/ngx_http_log_module.c

@@ -1134,9 +1134,7 @@
         }
 
     } else {
-        if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &value[1])
-            != NGX_OK)
-        {
+        if (ngx_conf_full_name(cf->cycle, &value[1], 0) != NGX_OK) {
             return NGX_CONF_ERROR;
         }
 

diff --git a/src/http/modules/ngx_http_xslt_filter_module.c b/src/http/modules/ngx_http_xslt_filter_module.c
index 6bf3828..9e85693 100644
--- a/src/http/modules/ngx_http_xslt_filter_module.c
+++ b/src/http/modules/ngx_http_xslt_filter_module.c

@@ -892,7 +892,7 @@
 
     ngx_memzero(sheet, sizeof(ngx_http_xslt_sheet_t));
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &value[1]) != NGX_OK) {
+    if (ngx_conf_full_name(cf->cycle, &value[1], 0) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 

diff --git a/src/http/modules/perl/ngx_http_perl_module.c b/src/http/modules/perl/ngx_http_perl_module.c
index a8a4184..90e32e8 100644
--- a/src/http/modules/perl/ngx_http_perl_module.c
+++ b/src/http/modules/perl/ngx_http_perl_module.c

@@ -485,9 +485,7 @@
     if (pmcf->modules != NGX_CONF_UNSET_PTR) {
         m = pmcf->modules->elts;
         for (i = 0; i < pmcf->modules->nelts; i++) {
-            if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &m[i])
-                != NGX_OK)
-            {
+            if (ngx_conf_full_name(cf->cycle, &m[i], 0) != NGX_OK) {
                 return NGX_CONF_ERROR;
             }
         }

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 5273fe3..ffe7fb4 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c

@@ -3686,9 +3686,7 @@
         if (prev->root.data == NULL) {
             ngx_str_set(&conf->root, "html");
 
-            if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &conf->root)
-                != NGX_OK)
-            {
+            if (ngx_conf_full_name(cf->cycle, &conf->root, 0) != NGX_OK) {
                 return NGX_CONF_ERROR;
             }
         }
@@ -4430,9 +4428,7 @@
     }
 
     if (clcf->root.data[0] != '$') {
-        if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &clcf->root)
-            != NGX_OK)
-        {
+        if (ngx_conf_full_name(cf->cycle, &clcf->root, 0) != NGX_OK) {
             return NGX_CONF_ERROR;
         }
     }

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 0b90c41..eacca59 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c

@@ -1626,9 +1626,7 @@
         cache->path->name.len--;
     }
 
-    if (ngx_get_full_name(cf->pool, &cf->cycle->prefix, &cache->path->name)
-        != NGX_OK)
-    {
+    if (ngx_conf_full_name(cf->cycle, &cache->path->name, 0) != NGX_OK) {
         return NGX_CONF_ERROR;
     }
 

diff --git a/src/http/ngx_http_script.c b/src/http/ngx_http_script.c
index 7af48ee..1da793b 100644
--- a/src/http/ngx_http_script.c
+++ b/src/http/ngx_http_script.c

@@ -131,12 +131,7 @@
     if ((v->len == 0 || v->data[0] != '$')
         && (ccv->conf_prefix || ccv->root_prefix))
     {
-        if (ngx_get_full_name(ccv->cf->pool,
-                              ccv->conf_prefix ? &ccv->cf->cycle->conf_prefix:
-                                                 &ccv->cf->cycle->prefix,
-                              v)
-            != NGX_OK)
-        {
+        if (ngx_conf_full_name(ccv->cf->cycle, v, ccv->conf_prefix) != NGX_OK) {
             return NGX_ERROR;
         }