diff --git a/mozilla/nsprpub/pr/src/pthreads/ptthread.c b/mozilla/nsprpub/pr/src/pthreads/ptthread.c
index c4ac2dca36d..9b98dd25c54 100644
--- a/mozilla/nsprpub/pr/src/pthreads/ptthread.c
+++ b/mozilla/nsprpub/pr/src/pthreads/ptthread.c
@@ -1631,11 +1631,11 @@ PR_IMPLEMENT(PRStatus) PR_SetCurrentThreadName(const char *name)
         return PR_FAILURE;
 
     PR_Free(thread->name);
-    nameLen = strlen(name) + 1;
-    thread->name = (char *)PR_Malloc(nameLen);
+    nameLen = strlen(name);
+    thread->name = (char *)PR_Malloc(nameLen + 1);
     if (!thread->name)
         return PR_FAILURE;
-    memcpy(thread->name, name, nameLen);
+    memcpy(thread->name, name, nameLen + 1);
 
 #if defined(OPENBSD) || defined(FREEBSD)
     result = pthread_set_name_np(thread->id, name);
@@ -1659,13 +1659,12 @@ PR_IMPLEMENT(PRStatus) PR_SetCurrentThreadName(const char *name)
 #define SETNAME_LENGTH_CONSTRAINT 15
 #define SETNAME_FRAGMENT1_LENGTH (SETNAME_LENGTH_CONSTRAINT >> 1)
 #define SETNAME_FRAGMENT2_LENGTH \
-    (SETNAME_LENGTH_CONSTRAINT - SETNAME_FRAGMENT1_LENGTH - 2)
+    (SETNAME_LENGTH_CONSTRAINT - SETNAME_FRAGMENT1_LENGTH - 1)
     char name_dup[SETNAME_LENGTH_CONSTRAINT + 1];
-    if (nameLen > SETNAME_LENGTH_CONSTRAINT + 1) {
+    if (nameLen > SETNAME_LENGTH_CONSTRAINT) {
         memcpy(name_dup, name, SETNAME_FRAGMENT1_LENGTH);
-        name_dup[SETNAME_FRAGMENT1_LENGTH] = '.';
-        name_dup[SETNAME_FRAGMENT1_LENGTH + 1] = '.';
-        memcpy(name_dup + SETNAME_FRAGMENT1_LENGTH + 2,
+        name_dup[SETNAME_FRAGMENT1_LENGTH] = '~';
+        memcpy(name_dup + SETNAME_FRAGMENT1_LENGTH + 1,
                name + nameLen - SETNAME_FRAGMENT2_LENGTH,
                SETNAME_FRAGMENT2_LENGTH);
         name_dup[SETNAME_LENGTH_CONSTRAINT] = '\0';
diff --git a/mozilla/nsprpub/pr/src/threads/combined/pruthr.c b/mozilla/nsprpub/pr/src/threads/combined/pruthr.c
index fa5f5209854..7ecccf555d9 100644
--- a/mozilla/nsprpub/pr/src/threads/combined/pruthr.c
+++ b/mozilla/nsprpub/pr/src/threads/combined/pruthr.c
@@ -1597,11 +1597,11 @@ PR_IMPLEMENT(PRStatus) PR_SetCurrentThreadName(const char *name)
         return PR_FAILURE;
 
     PR_Free(thread->name);
-    nameLen = strlen(name) + 1;
-    thread->name = (char *)PR_Malloc(nameLen);
+    nameLen = strlen(name);
+    thread->name = (char *)PR_Malloc(nameLen + 1);
     if (!thread->name)
         return PR_FAILURE;
-    memcpy(thread->name, name, nameLen);
+    memcpy(thread->name, name, nameLen + 1);
     _PR_MD_SET_CURRENT_THREAD_NAME(thread->name);
     return PR_SUCCESS;
 }