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authorRon Yorston2021-04-15 12:00:50 +0100
committerDenys Vlasenko2021-04-15 13:09:12 +0200
commit9b2a3895eedb3c46179b1ed923b0f1214da04c5b (patch)
treee6ef6bdf04d1e1aa46e426bcf50b6fd29ad3c5e7 /editors/vi.c
parentc0943ac451051b734711b0c95731ae7c515dbb31 (diff)
downloadbusybox-9b2a3895eedb3c46179b1ed923b0f1214da04c5b.zip
busybox-9b2a3895eedb3c46179b1ed923b0f1214da04c5b.tar.gz
vi: correctly record deleted characters
The undo queue didn't record deleted characters properly. For example, insert some text, backspace over a couple of characters then exit insert mode. At this point undo will restore two nulls instead of the deleted characters. The fix is in undo_push(): record the state of the UNDO_USE_SPOS flag and clear it before using 'u_type'. Also, update the comments to reflect the fact that UNDO_QUEUED_FLAG isn't actually used. function old new delta undo_push 443 435 -8 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-8) Total: -8 bytes Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'editors/vi.c')
-rw-r--r--editors/vi.c39
1 files changed, 22 insertions, 17 deletions
diff --git a/editors/vi.c b/editors/vi.c
index 31b5d3e..fef3281 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -399,26 +399,31 @@ struct globals {
#define UNDO_DEL 1
#define UNDO_INS_CHAIN 2
#define UNDO_DEL_CHAIN 3
-// UNDO_*_QUEUED must be equal to UNDO_xxx ORed with UNDO_QUEUED_FLAG
-#define UNDO_QUEUED_FLAG 4
+# if ENABLE_FEATURE_VI_UNDO_QUEUE
#define UNDO_INS_QUEUED 4
#define UNDO_DEL_QUEUED 5
-#define UNDO_USE_SPOS 32
-#define UNDO_EMPTY 64
+# endif
+
// Pass-through flags for functions that can be undone
#define NO_UNDO 0
#define ALLOW_UNDO 1
#define ALLOW_UNDO_CHAIN 2
# if ENABLE_FEATURE_VI_UNDO_QUEUE
#define ALLOW_UNDO_QUEUED 3
- char undo_queue_state;
+# else
+// If undo queuing disabled, don't invoke the missing queue logic
+#define ALLOW_UNDO_QUEUED ALLOW_UNDO
+# endif
+
+# if ENABLE_FEATURE_VI_UNDO_QUEUE
+#define UNDO_USE_SPOS 32
+#define UNDO_EMPTY 64
+ char undo_queue_state; // One of UNDO_INS, UNDO_DEL, UNDO_EMPTY
int undo_q;
char *undo_queue_spos; // Start position of queued operation
char undo_queue[CONFIG_FEATURE_VI_UNDO_QUEUE_MAX];
-# else
-// If undo queuing disabled, don't invoke the missing queue logic
-#define ALLOW_UNDO_QUEUED 1
# endif
+
struct undo_object {
struct undo_object *prev; // Linking back avoids list traversal (LIFO)
int start; // Offset where the data should be restored/deleted
@@ -1445,7 +1450,7 @@ static void yank_status(const char *op, const char *p, int cnt)
#endif /* FEATURE_VI_YANKMARK */
#if ENABLE_FEATURE_VI_UNDO
-static void undo_push(char *, unsigned, unsigned char);
+static void undo_push(char *, unsigned, int);
#endif
// open a hole in text[]
@@ -1572,9 +1577,12 @@ static void flush_undo_data(void)
// Undo functions and hooks added by Jody Bruchon (jody@jodybruchon.com)
// Add to the undo stack
-static void undo_push(char *src, unsigned length, uint8_t u_type)
+static void undo_push(char *src, unsigned length, int u_type)
{
struct undo_object *undo_entry;
+# if ENABLE_FEATURE_VI_UNDO_QUEUE
+ int use_spos = u_type & UNDO_USE_SPOS;
+# endif
// "u_type" values
// UNDO_INS: insertion, undo will remove from buffer
@@ -1583,8 +1591,8 @@ static void undo_push(char *src, unsigned length, uint8_t u_type)
// The CHAIN operations are for handling multiple operations that the user
// performs with a single action, i.e. REPLACE mode or find-and-replace commands
// UNDO_{INS,DEL}_QUEUED: If queuing feature is enabled, allow use of the queue
- // for the INS/DEL operation. The raw values should be equal to the values of
- // UNDO_{INS,DEL} ORed with UNDO_QUEUED_FLAG
+ // for the INS/DEL operation.
+ // UNDO_{INS,DEL} ORed with UNDO_USE_SPOS: commit the undo queue
# if ENABLE_FEATURE_VI_UNDO_QUEUE
// This undo queuing functionality groups multiple character typing or backspaces
@@ -1637,9 +1645,7 @@ static void undo_push(char *src, unsigned length, uint8_t u_type)
}
break;
}
-# else
- // If undo queuing is disabled, ignore the queuing flag entirely
- u_type = u_type & ~UNDO_QUEUED_FLAG;
+ u_type &= ~UNDO_USE_SPOS;
# endif
// Allocate a new undo object
@@ -1656,12 +1662,11 @@ static void undo_push(char *src, unsigned length, uint8_t u_type)
}
undo_entry->length = length;
# if ENABLE_FEATURE_VI_UNDO_QUEUE
- if ((u_type & UNDO_USE_SPOS) != 0) {
+ if (use_spos) {
undo_entry->start = undo_queue_spos - text; // use start position from queue
} else {
undo_entry->start = src - text; // use offset from start of text buffer
}
- u_type = (u_type & ~UNDO_USE_SPOS);
# else
undo_entry->start = src - text;
# endif