*** empty log message ***

diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index a408ef331867d5b8ff517b9d51b61a37046f7a44..fcce50f0b9a96243cc51fd493682c79a704336be 100644 (file)
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -177,6 +177,12 @@ def run_method_tests(test):
     test('replace', 'one!two!three!', 'one@two@three@', '!', '@')
     test('replace', 'one!two!three!', 'one!two!three!', 'x', '@')
     test('replace', 'one!two!three!', 'one!two!three!', 'x', '@', 2)
+    # Next three for SF bug 422088: [OSF1 alpha] string.replace(); died with
+    # MemoryError due to empty result (platform malloc issue when requesting
+    # 0 bytes).
+    test('replace', '123', '', '123', '')
+    test('replace', '123123', '', '123', '')
+    test('replace', '123x123', 'x', '123', '')
 
     test('startswith', 'hello', 1, 'he')
     test('startswith', 'hello', 1, 'hello')

diff --git a/Modules/stropmodule.c b/Modules/stropmodule.c
index 203feb942d556f79f8d593582fc1fd7f66f86042..abd27bcb706b633f2fc8b6794b52c78df5ecdf4b 100644 (file)
--- a/Modules/stropmodule.c
+++ b/Modules/stropmodule.c
@@ -1056,36 +1056,43 @@ static char *mymemreplace(char *str, int len, char *pat, int pat_len, char *sub,
                nfound = nfound > count ? count : nfound;
        if (nfound == 0)
                goto return_same;
+
        new_len = len + nfound*(sub_len - pat_len);
+       if (new_len == 0) {
+               out_s = "";
+       }
+       else {
+               assert(new_len > 0);
+               new_s = (char *)PyMem_MALLOC(new_len);
+               if (new_s == NULL)
+                       return NULL;
+               out_s = new_s;
 
-       new_s = (char *)PyMem_MALLOC(new_len);
-       if (new_s == NULL) return NULL;
+               while (len > 0) {
+                       /* find index of next instance of pattern */
+                       offset = mymemfind(str, len, pat, pat_len);
+                       if (offset == -1)
+                               break;
 
-       *out_len = new_len;
-       out_s = new_s;
-
-       while (len > 0) {
-               /* find index of next instance of pattern */
-               offset = mymemfind(str, len, pat, pat_len);
-               /* if not found,  break out of loop */
-               if (offset == -1) break;
-
-               /* copy non matching part of input string */
-               memcpy(new_s, str, offset); /* copy part of str before pat */
-               str += offset + pat_len; /* move str past pattern */
-               len -= offset + pat_len; /* reduce length of str remaining */
-
-               /* copy substitute into the output string */
-               new_s += offset; /* move new_s to dest for sub string */
-               memcpy(new_s, sub, sub_len); /* copy substring into new_s */
-               new_s += sub_len; /* offset new_s past sub string */
-
-               /* break when we've done count replacements */
-               if (--count == 0) break;
+                       /* copy non matching part of input string */
+                       memcpy(new_s, str, offset);
+                       str += offset + pat_len;
+                       len -= offset + pat_len;
+
+                       /* copy substitute into the output string */
+                       new_s += offset;
+                       memcpy(new_s, sub, sub_len);
+                       new_s += sub_len;
+
+                       /* note count==0 is effectively infinity */
+                       if (--count == 0)
+                               break;
+               }
+               /* copy any remaining values into output string */
+               if (len > 0)
+                       memcpy(new_s, str, len);
        }
-       /* copy any remaining values into output string */
-       if (len > 0)
-               memcpy(new_s, str, len);
+       *out_len = new_len;
        return out_s;
 
   return_same: