Fix early MySQL instance shutdown bug in error checking

The check_innodb_errors() function was using an overly broad error pattern
"\[ERROR\].*InnoDB" that matched warnings about missing tables in OTHER
databases, triggering premature shutdown even when the selected database
was healthy.

Changes:
1. Refactored check_innodb_errors() to accept optional database name parameter
2. Split error patterns into CRITICAL (always fail) and DATABASE_SPECIFIC
   - Critical errors: memory, plugin init, redo log corruption (always fail)
   - Database-specific errors: only fail if they mention the selected database
3. Removed the too-broad "\[ERROR\].*InnoDB" pattern
4. Updated both calls to check_innodb_errors() to pass DATABASE_NAME

This allows the script to:
- Succeed when other databases have issues (as they should be ignored)
- Only fail for actual problems with the selected database
- Properly attempt dump creation on the second instance

Fixes the 2-second gap between "ready for connections" and unexpected shutdown.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

modules/backup/mysql-restore-to-sql.sh

@@ -1079,6 +1079,7 @@ detect_recovery_level_from_errors() {
 check_innodb_errors() {
     local error_log="$1"
     local check_recent="${2:-no}"  # "yes" = only check recent errors, "no" = full check
+    local selected_db="${3:-}"     # Database name to filter on (optional)
 
     if [ ! -f "$error_log" ]; then
         return 0  # No error log yet, assume OK
@@ -1087,17 +1088,22 @@ check_innodb_errors() {
     local errors_found=0
     local critical_errors=()
 
-    # InnoDB critical error patterns
-    local error_patterns=(
+    # CRITICAL error patterns that ALWAYS fail (not specific to any database)
+    # These indicate fundamental InnoDB corruption or system issues
+    local critical_patterns=(
         "InnoDB: Corrupted"
         "InnoDB: Database page corruption"
-        "InnoDB: Unable to open"
         "InnoDB: Cannot allocate memory"
-        "InnoDB: Tablespace.*missing"
         "InnoDB: Redo log.*corrupt"
         "InnoDB:.*redo log.*incompatible"
         "InnoDB: Plugin initialization aborted"
-        "\[ERROR\].*InnoDB"
+    )
+
+    # DATABASE-SPECIFIC error patterns
+    # These only cause failure if they mention the selected database
+    local db_patterns=(
+        "InnoDB: Unable to open"
+        "InnoDB: Tablespace.*missing"
     )
 
     # If checking recent errors, only look at last 50 lines
@@ -1108,8 +1114,8 @@ check_innodb_errors() {
         log_content=$(cat "$error_log" 2>/dev/null)
     fi
 
-    # Check each pattern
-    for pattern in "${error_patterns[@]}"; do
+    # Check CRITICAL patterns first (always fail if found)
+    for pattern in "${critical_patterns[@]}"; do
         if echo "$log_content" | grep -qE "$pattern"; then
             local error_line=$(echo "$log_content" | grep -E "$pattern" | tail -1)
             critical_errors+=("$error_line")
@@ -1117,6 +1123,19 @@ check_innodb_errors() {
         fi
     done
 
+    # Check DATABASE-SPECIFIC patterns only if they mention the selected database
+    if [ -n "$selected_db" ]; then
+        for pattern in "${db_patterns[@]}"; do
+            # Create pattern that checks both for the error pattern AND the database name
+            # The error message will contain backticks like: `database_name`.`table_name`
+            if echo "$log_content" | grep -qE "$pattern.*\`${selected_db}\`"; then
+                local error_line=$(echo "$log_content" | grep -E "$pattern.*\`${selected_db}\`" | tail -1)
+                critical_errors+=("$error_line")
+                errors_found=$((errors_found + 1))
+            fi
+        done
+    fi
+
     if [ -n "$errors_found" ] && [ "$errors_found" -gt 0 ]; then
         print_error "InnoDB errors detected in $error_log:"
         for err in "${critical_errors[@]}"; do
@@ -1767,9 +1786,10 @@ start_second_instance() {
             sleep 2
 
             # Check for InnoDB errors in the error log
+            # Pass the selected database name so we only fail on relevant errors
             echo ""
             print_info "Checking InnoDB startup status..."
-            if ! check_innodb_errors "$datadir/mysql.err" "yes"; then
+            if ! check_innodb_errors "$datadir/mysql.err" "yes" "$DATABASE_NAME"; then
                 print_error "InnoDB initialization encountered errors"
                 echo ""
                 print_warning "Attempting to shut down second instance..."
@@ -1813,8 +1833,8 @@ start_second_instance() {
         print_error "Second MySQL instance failed to start"
         echo ""
 
-        # Check for InnoDB errors
-        if ! check_innodb_errors "$datadir/mysql.err" "no"; then
+        # Check for InnoDB errors (pass selected database for filtering)
+        if ! check_innodb_errors "$datadir/mysql.err" "no" "$DATABASE_NAME"; then
             echo ""
         fi