Cleanup, added some explanation/comments

diff --git a/libraries/liblber/decode.c b/libraries/liblber/decode.c
index 33dff6bec787121db58ca8100bbfb19de7c11300..6e16c2159eb575c8fd2fda80f13c62a80179939c 100644 (file)
--- a/libraries/liblber/decode.c
+++ b/libraries/liblber/decode.c
@@ -278,8 +278,13 @@ ber_get_stringb(
        return tag;
 }
 
+/* Definitions for recursive get_string */
+
 enum bgbvc { ChArray, BvArray, BvVec };
 
+/* Use this single cookie for state, to keep actual
+ * stack use to the absolute minimum.
+ */
 typedef struct bgbvr {
        BerElement *ber;
        enum bgbvc choice;
@@ -293,6 +298,10 @@ typedef struct bgbvr {
        } res;
 } bgbvr;
 
+/* Recursive get_string, for decoding a vector of strings. The number
+ * of elements in the vector is limited only by available stack space.
+ * Each invocation consumes 24 bytes of stack on a 32-bit machine.
+ */
 ber_tag_t
 ber_get_stringbvr( bgbvr *b, int n )
 {
@@ -309,7 +318,7 @@ ber_get_stringbvr( bgbvr *b, int n )
                        *b->res.c = NULL;
                        return 0;
                }
-               /* do the allocation */
+               /* Allocate the result vector */
                switch (b->choice) {
                case ChArray:
                        *b->res.c = LBER_MALLOC( (n+1) * sizeof( char * ));
@@ -324,9 +333,15 @@ ber_get_stringbvr( bgbvr *b, int n )
                        (*b->res.bv)[n] = NULL;
                        break;
                }
+               /* Did the malloc succeed? */
+               if ( *b->res.c == NULL )
+                       return LBER_DEFAULT;
                return 0;
        }
 
+       /* Do all local allocs before the recursion. Then there
+        * cannot possibly be any failures on the return trip.
+        */
        if ( b->choice == BvVec )
                bvp = LBER_MALLOC( sizeof( struct berval ));
 
@@ -336,6 +351,7 @@ ber_get_stringbvr( bgbvr *b, int n )
        }
 
        b->tag = ber_get_stringbvr( b, n+1 );
+       
        if ( b->tag == 0 )
        {
                /* store my result */
@@ -352,6 +368,9 @@ ber_get_stringbvr( bgbvr *b, int n )
                        break;
                }
        } else {
+               /* Failure will propagate up and free in reverse
+                * order, which is actually ideal.
+                */
                if ( bvp ) LBER_FREE( bvp );
                LBER_FREE( bv.bv_val );
        }
@@ -549,6 +568,7 @@ ber_next_element(
 }
 
 /* Hopefully no one sends vectors with more elements than this */
+/* Don't define this! ber_get_stringbvr works much much better! */
 /* #define     TMP_SLOTS       1024 */
 
 /* VARARGS */