1 files changed, 23 insertions, 1 deletions
diff --git a/src/libenvexec/env_merge.c b/src/libenvexec/env_merge.c
index ac3e17c..b6281ee 100644
--- a/src/libenvexec/env_merge.c
+++ b/src/libenvexec/env_merge.c
@@ -1,9 +1,31 @@
 /* ISC license. */
 
+#include <string.h>
+#include <errno.h>
+
 #include <skalibs/bytestr.h>
 #include <skalibs/env.h>
 
 size_t env_merge (char const **v, size_t vmax, char const *const *envp, size_t envlen, char const *modifs, size_t modiflen)
 {
-  return env_mergen(v, vmax, envp, envlen, modifs, modiflen, byte_count(modifs, modiflen, '\0')) ;
+  size_t vlen = envlen ;
+  size_t i = 0 ;
+  if (envlen >= vmax) return 0 ;
+  for (; i < envlen ; i++) v[i] = envp[i] ;
+  for (i = 0 ; i < modiflen ; i += strlen(modifs + i) + 1)
+  {
+    size_t split = str_chr(modifs + i, '=') ;
+    size_t j = 0 ;
+    for (; j < vlen ; j++)
+      if (!strncmp(modifs + i, v[j], split) && (v[j][split] == '=')) break ;
+    if (j < vlen) v[j] = v[--vlen] ;
+    if (modifs[i + split])
+    {
+      if (vlen >= vmax) return 0 ;
+      v[vlen++] = modifs + i ;
+    }
+  }
+  if (vlen >= vmax) return 0 ;
+  v[vlen++] = 0 ;
+  return vlen ;
 }